History

Delmonico steak:  a mystery solved

By JOE O'CONNELL, Food Writer
First posted 25 August 2001 at 1525 GMT
Last updated 30 November 2003 at 1702 GMT

NEW YORK, New York -- The Delmonico Steak is one of the most desirable and well-known steaks on the market.  It originated between 1840 and 1850 as the house cut at Delmonico's Restaurant in lower Manhattan. 

However, there is a problem with the modern name "Delmonico Steak":  no one seems to remember the exact cut of beef that was the original, authentic Delmonico Steak.

The problem is that the meaning of the Delmonico Steak changed over the years and from place to place.  More than 150 years after the Delmonico Steak was first offered to customers as the "best steak available", the identify of that original cut has been lost.  Or has it?  The name is regularly used today as a synonym for a club steak, a New York strip steak, a boneless rib-eye steak, and several other cuts, as described below.

So, what was the steak which was used originally at Delmonico's restaurant?  What is an authentic Delmonico steak?

Different claims

Many authorities on steak make different claims about the identity of the authentic Delmonico Steak.  The name Delmonico Steak is used for many different cuts.  In fact, various authoritative sources assert that at least eight different cuts are the real Delmonico Steak!  

Here are the eight different cuts which various authorities claim to be the original, authentic cut for the Delmonico Steak, starting with the cut closest to the beef's head (anterior) and moving back (posterior).

1.  Last boneless chuck-eye steak

See the Cook's Thesaurus on Beef Chuck.

2.  Any bone-in rib steak

According the Fabulous Foods Cooking School, the Delmonico Steak is a bone-in rib steak (not to be confused with the bone-in rib-eye steak, which is a different cut, as described below).

Made famous at Delmonico's Restaurant in New York, this is a large steak that is usually cut one rib thick and has a fair amount of marbling.  A bone-in cut, Delmonicos are usually between one and two inches thick.  Id.

3.  Any bone-in rib-eye steak

Emeril Lagasse, the well-known chef who has started a chain of Delmonico Restaurants in several cities, refers to the Delmonico Steak as a bone-in rib-eye steak.  See his recipe for Delmonico's Dry Aged Rib-Eyes.

The CalBeef website agrees but says that the term is used both for the bone-in rib-eye steak as well as the bone-in top loin steak.

4.  First boneless rib-eye steak

According to Art in Steaks, the Delmonico steak is the first cut (nearest the chuck or front end) of the boneless rib-eye:

Delmonico is the eye of the rib (called ``Rib-Eye" in meat circles).  It is known, generally, for its richness; because of the greater quantity of fine fat grains -- especially in the outer part of the eye and especially when cut nearer to the chuck end.  Some people mistake this outer section for ``tail" or flank, but it is absolutely the sweetest and juiciest of beef eating (in our opinion) in the world.  Id.

5.  Any boneless rib-eye steak

California's Harris Ranch uses the term Delmonico steak for either a boneless rib-eye steak (also called a fillet steak) or a boneless top loin steak (also called a strip, shell or club steak ).  See Harris Ranch Popular Beef Cuts.  Prince Meat Company's Entrees to Excellence also equates the Delmonico steak and the boneless rib-eye steak.

Chris Schlesigner, co-author of License to Grill, uses the term for a rib eye.  See his recipe for "Grilled Delmonico Steak Adobo" here and also here.  See also the BestBeef.com recipe for Delmonico.  Steven Raichlin, author of How to Grill, refers to the Delmonico steak as a rib-eye steak in a story entitled "Steak of the Union".  Other sites, including restaurant websites, seem to use Delmonico steak as a synonym of the boneless rib-eye steak.  See, e.g., Gallagher's menu and many other restaurants that will be found with a routine web search of "Delmonico steak."

In a telephone conversation on September 24, 2001 at 3:45 PM PDT (2245 GMT), the manager of Delmonico's Restaurant in New York City, Corrado, said that the Delmonico steak is a boneless rib-eye cut from any part of the rib-eye.  The Delmonico chef, Angelo Panageas, agrees.

Foodies.com tips says, 

"Delmonico" is a fancy name for ribeye. You'll find the word Delmonico more commonly in the Northeast (the original Delmonico's Restaurant was in NYC); ribeye is the label of choice in the Southeast.  Id (citing the National Cattlemen's Beef Association source).

According to the official Canadian government's food inspection website, Delmonico steak means a rib-eye steak.  Even Julia Child (Child at 191) and Martha Stewart agree that the Delmonico Steak is a rib-eye cut.

Finally, the well-known barbecue site, Barbecuen.com, claims in "Meat Cuts & Tenderness" that the Delmonico steak is an ordinary rib-eye steak.

6.  First bone-in top loin steak

According to the Culinary Cafe, the Delmonico steak is also called a club steak, but both names refer to Delmonico's Restaurant and refer to the first cut of the bone-in top loin, adjacent to the rib section.  The steak is triangular, but smaller than a T-bone.  See the Culinary Cafe Glossary.

7.  Any bone-in top loin steak

The Gourmet Emporium says, 

The Delmonico Steak is simply a New York Strip Steak with the bone left in, giving this already delicious steak an extra boost of flavor.  Id.

Similarly, the Gourmet Sleuth Guide to Beef Cuts says that the Delmonico Steak means either a bone-in top loin or a rib-eye. 

The famous Pacific Dining Car Restaurant in Los Angeles agrees on its menu, saying that the Delmonico steak is a "turn-of-the-century favorite . . . a New York strip steak with the bone still in for the sweetest taste of beef."  See, also, the Official Pacific Dining Car website menu and the CitySearch Review here.

According to the authoritative Lobel's butcher in New York, its "Beef:  A Primer on Steaks" says:

Club Steak -- Also called Delmonico, after the famed 19th century New York dining club that served this steak exclusively.  The club steak is rectangular in shape.  It is smaller than the T-bone but has the same large "eye" section with no tenderloin.  The club is cut from the short loin, next to the rib end.  This is a delicious and tender steak when properly cut.  When you buy a club steak, take a good look at the steak's "eye."  The meat should be fine in texture with delicate marbling.  If the meat seems coarse and contains fat chunks, you will know this is not the quality you want.  Id.

Greg's Quality Market http://www.mwt.net/~ghmahveh/has almost exactly the same description (except only that the shape is described as triangular):

Club Steak -- Sometimes called Delmonico, after the famed 19th century New York dining club which served this steak exclusively, the club steak is triangular in shape.  It is smaller than the T-bone but has the same large "eye" section with no tenderloin.  The club is cut from the short loin, next to the rib end.  When cut properly, this is a delicious and tender steak.  When you buy a club steak from a new butcher, take a good look at the steak's "eye."  The meat should be fine in texture with delicate marbling.  If the meat seems coarse and contains fat chunks, you will know it is not the quality you want.  Id.

8.  Any boneless top loin steak

According to the FoodTV Encyclopedia for Delmonico Steak, the Delmonico steak is a boneless top loin steak, which is also called a New York strip steak and a Kansas City strip steak.  (With the bone in, it is usually called a club steak.)

InfoPlease article on food names agrees and says that the Delmonico steak is a boneless top loin, also called the New York strip and Kansas City strip.  See also the Learning Network.  The AllRecipes entry for Delmonico steak agrees, as does the Epicurious dictionary entry for Delmonico steak and the American Heritage Dictionary (at Bartleby) for Delmonico steak, but which also says that it is synonymous with club steak.

California's Harris Ranch uses the term Delmonico steak for either boneless top loin steak (also called a strip, shell or club steak ) or a boneless rib-eye steak (also called a fillet steak).  See Harris Ranch Popular Beef Cuts.  

Conclusion

An exhaustive analysis of authorities identifies eight cuts as being the cut used in the original, authentic Delmonico Steak.  None of these authorities is correct!

Our research of the historical record has found the identity of the original, authentic cut.

The original, authentic Delmonico steak

To resolve the question of which of these nine candidates is the original, authentic Delmonico steak, the two original masters themselves were consulted.  As described in a related story on the history of Delmonico's Restaurant, Alessandro Filippini and Charles Ranhofer each served as chef de cuisine at Delmonico's Restaurant in the 19th Century, and each was largely responsible for building the reputation of the restaurant as the finest in the United States and one of the finest in the world.

Filippini and Ranhofer each wrote a treatise on food preparation.  Filippini wrote The Table  and The International Cook Book (which were both written for the non-professional home cook), and Ranhofer wrote The Epicurean (which was written for the professional chef).  Each author included recipes and described food preparation techniques from Delmonico's Restaurant.  

Filippini and Ranhofer provided the recipe for the Delmonico Steak, and their recipes are essentially the same.

Filippini's recipe

Alessandro Filippini provides the recipe for the Delmonico Steak as Recipe Number 812 at page 233 of The International Cook Book.  Of the thousands of recipes in the this treatise and in The Table, Filippini gives only this recipe for Delmonico Steak, and this is the only recipe uses the word Delmonico for any kind of steak or beef dish.

812.  Delmonico's Steaks, Bordelaise

Nicely trim and lightly flatten with a cleaver two tender sirloin steaks of one and a quarter pounds each.  Mix on a plate one teaspoon salt, half teaspoon white pepper, and a tablespoon oil and gently roll the steaks in the seasoning;  arrange on a broiler and broil on a brisk [charcoal] fire for eight minutes on each side.  Remove and dress on a hot dish.  Pour hot Bordelaise sauce, prepared as per [Recipe] No. 28, over and serve.  Id at 233. 

It should be noted that the addition of the Bordelaise sauce changes the name from the basic Delmonico's Steak to the "Demonico's Steaks, Bordelaise" (which is given in the plural, because two sirloin steaks are used in the single recipe, because the recipe was designed as a single meal for guests).

Ranhofer's recipe

Ranhofer provides the recipe for the Delmonico Steak as Recipe Number 1375 at page 487 of The Epicurean.  Of the 3,500 recipes in the treatise, Ranhofer gives only this recipe, which uses the word Delmonico for any kind of steak or beef dish.

[Recipe Number] (1375).  Delmonico Sirloin Steak of Twenty Ounces, Plain (Bifteck de Contrefilet Delmonico de Vingt Onces, Nature).

Cut from a sirloin slices two inches in thickness;  beat them to flatten them to an inch and a half thick, trim nicely;  they should now weigh twenty ounces each;  salt them on both sides, baste them over with oil or melted butter, and broil them on a moderate fire for fourteen minutes if desired very rare;  eighteen to be done properly, and twenty-two to be well done.  Set them on a hot dish with a little clear gravy ([Recipe] No. 404) or maitre d'hotel butter ([Recipe] No. 581).  Ranhofer at 487.

Ranhofer follows this plain version of the Delmonico Steak with two others versions of the same steak which, like Filippini's versions, are served with a different sauce:  a la Perigueux and Spanish style.

It is clear from Ranhofer's illustration, Fig. 311, that the sirloin steak is boneless.  Ranhofer, Fig. 311 at 487.  Because Ranhofer teaches the use of the finest ingredients, one may reasonably assume that the proper sirloin is the best available:  a boneless, Prime-Grade, dry-aged, top sirloin (IMPS 181A).  More information about this cut is available on the webpage about the nine different Sirloin Steaks.

Solution or another mystery?

This should have laid to rest the controversy about which cut of beef is used in the original, authentic Delmonico steak.  But how is it that even Delmonico's Restaurant in New York City -- even though the restaurant is not a real successor to the original Delmonico's -- how is it that this new Delmonico's does not use the authentic cut for its Delmonico Steak?  

Is it possible that the solution above -- relying on the recipes of two of the restaurant's great chefs de cuisine -- is not the correct solution, after all?  How did this state of affairs come about?  How is it that some many authorities claim that different cuts of meat are the authentic Delmonico Steak?  Perhaps the mystery has not yet been solved, and there are two plausible and interesting theories.

Delmonico means merely "the best"

By 1868, after the United States had recovered from the Civil War, the fame of Delmonico's Restaurant (or, more properly, restaurants, because by then there were four Delmoico's Restaurant locations in New York) continued to grow.  First by newspapers and then by the railroad and telegraph, the name and feats at Delmonico's spread across the land.  

For example, in 1873, a wealthy importer prevailed on Lorenzo Delmonico and his famous chef, Charles Ranhofer, to spare no cost in giving a banquet that would be the talk of the world.  The was to be a carte blanche  dinner, which meant that without limitation as to cost.  The affair was retold thus:

In Delmonico's largest room an oval table was constructed, to seat seventy-five guests.  The table filled the entire floor space except for a passage just wide enough for the waiters to circulate.  The center of the table was a lake thirty feet long, landscaped with exotic plants, waterfalls, violet-bordered brooks, blossoming hillocks and grassy glades.  The lake was enclosed by a mesh of gold wire extending to the ceiling, and this formed a cage for several swans that glided upon the water;  Tiffany had constructed the cage, and the swans were on loan from Prospect Park in Brooklyn.  Around the foot of the wire screen was an embankment of flowers to protect the diners from splashing when the swans now and then fought.  Over the lake were suspended golden cages containing songbirds.  The entire Delmonico's staff was summoned to admire this aquatic-gastronomic masterpiece, and the "Swan Dinner" went down in legend.  Thomas at 149.

The name Delmonico had long before entered the general usage and become synonymous with "the best".  Americans in Chicago, Denver, New Orleans and San Francisco, who had never seen and would never see much less dine at a Delmonico's Restaurant, used with word with a full understanding of its meaning.

With this background, the theory may be explained.  It is very possible that patrons of restaurants across America asked their chefs for a "Delmonico Steak", meaning by that that they wanted the "best steak in the house".  Naturally, the chefs obliged their patrons' requests, some with ribeye, some with top loin, others with tenderloin, and so forth.  This would explain the many different meanings, across the U.S. and across time, for Delmonico Steak.

One authority agrees

One authority who agrees with the foregoing is a butcher who is an authority on meat cuts.  Craig Meyer, who has been a meatcutter for more than 30 years and who maintains the Ask the Meatman FAQ, gives the following:

Question:  What is the cut of beef that is called Delmonico Dteak?  Do they cut these steaks any more and what should I ask for at the super market?  Thank you.

Answer:  There are more than sixty different beef cuts in the meat case today.  Add in the fact that many cuts have several different names and the meat case can be very confusing.

And a steak may be labeled a certain name in one area of the U.S., and the same labeled name in another area might be a completely different cut of steak.

In my area, Southeast Missouri, a Delmonico steak was a Boneless Top Sirloin beef steak.

In other parts of the country, a Delmonico was was a Bone-In Top Loin Steak (cut from the short loin), or a Rib-Eye Steak (cut from the rib).

So, unless you know if the Delmonico steak you have had before was cut from:  the Short Loin, Sirloin, or Rib, it's hard to tell exactly what you have eaten before as a Delmonico steak.

You could possible look at the above three choices labeled as such in the grocery's meat case, and see if one of those "looked" like what you had before. If so, then go with that one.

I know this wasn't a quick easy answer, but there really isn't one. But I hope this sets you out on the right path.  (Emphasis added.)  Id.

Sirloin changed meanings

There is a second, plausible explanation for the fact that both Filippini's and Ranhofer's recipes for the Delmonico Steak call for the "sirloin steak" yet modern authorities never use "sirloin steak."  The explanation might be that the meaning of the word "sirloin" changed over the last hundred years, so that what Filippini and Ranhofer described as the "sirloin" is not what is known today as the "sirloin".

In the French language, the word sur means above or over.  In beef, the long narrow tender muscle that runs along the inside of the rib cage on either side of the spine is called the tenderloin.  

The following summarizes the theory of the meaning of the French sur:

In the 19th Century, the tenderloin muscle was called the loin (in French, le loigne).  This was the name given to the entire area of cattle in the area of the lower back and, more particularly, to the muscle that ran along the inside of the rib cage on either side of the spine.

A long back muscle runs along the outside of the rib cage on either side of the spine.  Because this muscle was above the loin muscle, the French butchers and cooks called it the sur loigne, which translated into the English language as the similarly sounding sirloin.  

Only later was this long back muscle subdivided into the chuck (front shoulder), rib, top loin and sirloin portions.

Therefore, a 19th Century recipe that called for a "sirloin steak" did not refer to a modern sirloin steak but instead meant any steak taken from the entire length of the back muscle, including the chuck, rib, top loin and sirloin portions.

If the analysis concluded at this point, then the result would be that the Delmonico Steak means all eight or nine cuts, as claimed by the various authorities mentioned above!  All their claims would be correct, because the Delmonico Steak would mean the cut from any portion of the entire back muscle, from the chuck-eye, through the rib-eye and top loin, and including the modern-day sirloin cut.

Note that both Filippini and Ranhofer referred to sirloin steak in their books published between 1900 and 1910, so that is the critical time period in which to determine if the word meant the entire back muscle or the modern-day sirloin.  

Evidence supports of the theory that the word sirloin steak meant more than merely the modern usage.  That is in Filippini's recipe for Entrecotes, in which he calls for the use of a "sirloin steak".  See Recipe No. 1483.  The modern word entrecotes is from the French words entre cotes, which means literally "between ribs".  The entrecote cut is thus the rib steak (with or without the bone).

Meaning of sirloin

The solution to the sirloin mystery nears.

Meaning and etymology

According to the Oxford English Dictionary ("OED"), the English word sirloin is derived from the French words sur loigne, which means "above the loin".  OED.  According to the OED, sirloin means:

1. The upper and choicer part of a loin of beef, used for roasting.  Id.

The OED explains the fictitious etymology variously stated in the following quotations: 

1655 Fuller.  A Sir-loyne of beef was set before Him (so knighted, saith tradition, by this King Henry VIII) 

1731 Swift.  But, pray, why is it called a Sir-loyn?  Why, our King James First, being invited to dinner by one of his nobles, and seeing a large Loyn of Beef at his Table, drew out his sword and knighted it.

1822 Cook's Oracle.  Sir-Loin of Beef.  This joint is said to owe its name to King Charles the Second, who dining upon a Loin of Beef, said for its merit it should be knighted, and henceforth called Sir-Loin.

Synonymous with top loin

The 19th Century meaning of sirloin included the entire top loin muscles, which runs from the modern cuts called chuck eye, through the rib-eye and top loin, and down to and including the sirloin.  Note that modern usage identifies the individual muscles of each cut of meat, but in the 19th Century, the entire bundle of related muscles were treated as one.  As an example of this usage, consider the Porterhouse Steak.  

The Porterhouse includes the bone (part of the spine and the riblet) which separates the modern-day tenderloin muscle (which is inside the rib cage -- or more precisely, inside the body cavity where the rib cage would be, if it extended that far down) and the modern-day top loin (which is outside the rib cage).  In modern usage, the Porterhouse does not include the sirloin -- the sirloin begins farther down.  

With this background, consider the following excerpt from A Tramp Abroad, which was written by Samuel Clemens (Mark Twain) in 1894:  

[It was] a mighty porterhouse steak an inch and a half thick, hot and sputtering from the griddle; dusted with fragrant pepper; enriched with little melting bits of butter of the most unimpeachable freshness and genuineness;  the precious juices of the meat trickling out and joining the gravy, archipelagoed with mushrooms; a township or two of tender, yellowish fat gracing an outlying district of this ample country of beefsteak;  the long white bone which divides the sirloin from the tenderloin still in place.  (Emphasis added.)  Clemens Tramp at Chap. 49, "Hanged with a Golden Rope."

This shows that, in the 19th Century, the word sirloin meant or at least included the entire muscle which in modern usage is the top loin.

This also confirms the confusion in meat nomenclature, particularly before 1973, when the National Live Stock and Meat Board recommended about 300 standard names be used for cuts of meat (which were selected from thousands of regional names that confuse customers as to what they are getting).

Usage by Ranhofer

In his 1894 treatise The Epicurean, Ranhofer described many terms.  Ranhofer describes the use of only four major sections of beef:

• Fillet
• Loin, Flat Bone
• Loin, Hip Bone
• Loin, Short

Notice that he did not describe a separate section of meat called the sirloin, which is expected if at the time the word sirloin referred to a secion of beef and not just a cut.  Ranhofer at 21.

Terms changed from then to now.  In modern usage, the Prime Rib refers to the best bone-in roast cut from the back (posterior) of the Rib Section, which is from the 6th to the 12th rib, inclusive, and which is in front of (anterior) to the Short Loin Section.  In the time of Delmonico's Restaurant, however, Rahnofer wrote this about the Prime Rib:

American roast beef is taken from the ribs;  sometimes seven ribs are served [note that this corresponds with the modern usage, in which the Rib Section is comprised of seven ribs, being the 6th through the 12th, inclusive], but the piece containing six [by which is meant the cut containing the 7th through the 12th ribs, inclusive] is far more advantageous, while the four rib piece [the 9th through the 12th ribs, inclusive], cut from the short loin is better still.  Ranhofer at 177-178.

Note:  It is possible that Ranhofer included the 13th rib in the Prime Rib.  In this case, Ranhofer included either eight ribs in the entire rib section (the 6th through the 13th ribs) or seven ribs (the 7th through the 13th ribs).

That is, the terms of beef sections and cuts have changed significantly between then and now.

Note:  it can be inferred that, for Ranhofer, the Short Loin included three parts -- the Front Short Loin, the Middle Short Loin and the Back Short Loin -- and that, for Ranhofer, the Middle Short Loin was the same as the modern term for Short Loin.  Ranhofer at 481.  Ranhofer called the Hip what modern usage calls the Sirloin.  Ranhofer at 472.

In the 19th Century, there is no doubt that the sirloin meant the entire back muscle which begins at the ribs (beginning with the modern Chuck Eye), proceeds through the ribs and loin (through the modern Rib Eye and Top Loin), and ends in front of the hip (and includes the modern Top Sirloin).  Recall that, in modern usage, the sirloin section is behind the short loin.  Consider the following usages from the 19th Century:

Remove the sirloin from a piece of middle short loin . . . . Ranhofer at 482.

Take a sirloin from a short loin . . . . Ranhofer at 484.

The question is settled with Ranhofer's discussion of how to cut a Porterhouse Steak.  The Porterhouse Steak is a bone-in steak cut from (in modern terms) the short loin and contains a piece of top loin and a piece of tenderloin.  But Ranhofer uses different terms:  

([Recipe No.] 1362.)  Porterhouse Steak (Bifteck d'Aloyau).

Select a good, fleshy middle short loin, the meat being pink and very tender.  Cut slices an inch and three-quarters thick, in the tenderloin and sirloin, sawing away the spine bone form the rib.  Cut off the fat and sinews, and trim it nicely to the shape of the accompanying [illustration];  after trimming it should weigh two pounds and a quarter.  Ranhofer at 485.

In modern terms, the steak would be described as cut "in the tenderloin and top loin".

Delmonico Steak

In French, the word bifteck means steak.  The French word contrefilet meant sirloin in Ranhofer's time, or top loin in modern usage.  Therefore, a bifteck de contrefilet in Ranhofer's time was called a sirloin steak but in modern usage is called a top loin steak.  Now again consider Ranhofer's recipe for the Delmonico Steak:

[Recipe Number] (1375).  Delmonico Sirloin Steak of Twenty Ounces, Plain (Bifteck de Contrefilet Delmonico de Vingt Onces, Nature).

Cut from a sirloin slices two inches in thickness;  beat them to flatten them to an inch and a half thick, trim nicely;  they should now weigh twenty ounces each . . . . Ranhofer at 487.

Both the words used by Ranhofer and the illustration given confirm the fact that the original, authentic Delmonico Steak, as served at Delmonico's Restaurant in the 19th Century, was a boneless top loin.  About this, there can now be no doubt whatsoever.

In Ranhofer's time, the sirloin included the entire back muscle which, in modern terms, would have included the chuck eye, rib eye, top loin and top sirloin.  However, the evidence shows that the Delmonico Steak was cut from (in modern terms) in back of (posterior to) the rib sectiona and in front of (anterior to) the cuts of the Porterhouse Steak.  This is supported by the following facts:

• Delmonico's Restaurant regularly served Prime Rib (which, as shown above, is cut from the middle of, in Ranhofer's terms, the sirloin;  and
• Delmonico's Restaurant regularly served Porterhouse Steaks, which are cut from the back of, in Ranhofer's terms, the sirloin, where it adjoins the tenderloin.

Using modern terminology, the Delmonico Steak is the steak which is cut between the end of the rib section and the first Porterhouse Steak.  In modern terms, this is the first (anterior) few inches of the Short Loin have no tenderloin.  When boneless, this Top Loin Steak is the original, authentic Delmonico Steak.

Finally, the analysis shows that there could have been an argument that the Delmonico Steak could have been cut from in front of (anterior to) (in Ranhofer's terms) the Prime Ribs.  As shown above, this could mean that the Delmonico Steak was either (in modern terms) the last (posterior) chuck eye or the first (anterior) rib-eye.  Ranhofer's words might allow either of these possibilities, but two facts negate it:

• First, Delmonico's Restaurant served only the best of the best.  In the 19th Century, beef was not as good as today's, and the chuck eye steak and the rib-eye steak were not as tender or as flavorful as other cuts.  Ranhofer assuredly would not put the name of his restaurant on an inferior (less tender and less flavorful) cut.
• Second, the entire issue is disposed by reference to Ranhofer's illustration of the Delmonico Steak, which is clearly (in modern terms) a boneless top loin steak.  Ranhofer at 487.

Conclusion

The long journey to trace the identify of the original, authentic Delmonico Steak has concluded.  The solution of the original mystery created another mystery, but all now is clear.

The original, authentic Delmonico Steak is not a bone-in steak.  It is not a chuck-eye steak, a rib-eye steak, a porterhouse steak, or a sirloin steak.  And it is not any boneless top loin.  These are great steaks, but none is the Delmonico Steak.

The historical fact is that the original, authentic Delmonico Steak is, in modern terms, the first boneless top loin steak cut from the front of (anterior to) the short loin.

Related information

• History of Delmonico's Restaurant
• Delmonico Steak
• Delmonico Potatoes
• Delmonico bibliography