Food historians generally agree the dish is named for Arthur Wellesley, First Duke of Wellington, the man who crushed Napoleon at Waterloo.
"Volumes have been written about Wellington the soldier, but the dish that bears his name is surprisingly elusive. Almost certainly the pastry covering was at first a mere paste of flour and water, wrapped around the uncooked tenderloin so that it would roast without browning, a culinary fad of the era. In time the covering became puff pastry and an integral part of the dish. Then the chefs on the continent, with their oft-noted penchant for lily-gilding, inserted a layer of truffles and pate de foie gras, today often simplified to mushrooms and chicken livers...In Ireland Beef Wellington, sometimes called Wellington Steak, remains a simple combination of excellent rare beef and flaky pastry. The dish is also known in France, where, not surprisingly, it is simply called filet de boeuf in croute."
---Rare Bits: Unusual Origins of Popular Recipes, Patricia Bunning Stevens [Ohio University Press:Athens] 1998 (p. 95-6)
"I am persuaded that beef Wellington is of Irish origin. In Irish Traditional Food, Theodora FitzGibbon offers a recipe for Steig Wellington, using the Irish spelling for steak. She prefaces the recipe with the statement that "this was said to be a favorite of the Duke of Wellington, and it is sometimes also known as beef Wellington.""
---Craig Claiborne's The New York Times Food Encyclopedia, compiled by Joan Whitman [Times Books:New York] 1985 (p. 34-5)
"Jane Garmey includes it [Beef Wellington] in Great British Cooking: A Well Kept Secret, (1981), but admits that the recipe's origin is a mystery. "I have never been able to find a reference to Beef Wellington in any British cookery book, old or new," she writes in her recipe headnote. "However, since...cooking meat in a pastry case was fairly common at the end of the eighteenth century and since this is a rather special way to prepare a beef fillet, it would seem unfair to omit Beef Wellington for its dubious heritage." Strangely, Adrian Baily makes no mention of Beef Wellington in The Cooking of the British Isles, (1969), a time when this fussy recipe was in vogue in this country (it was said to be President Nixon's favorite). Beef Wellington...became a showpiece of ambitious 60s hostesses...Before long there were shortcut versions with canned liver paste substituting for foie gras, canned mushrooms for duxelles, and refrigerator crescent rolls or any frozen pastry shells for puff pastry. There was even Hamburger a la Wellington (House Beautiful Magazine, January 1970). By the 80s, however, it was over. Beef Wellington had lost its cachet."
---American Century Cookbook: The Most Popular Recipes of the 20th Century, Jean Anderson [Clarkson Potter:New York] 1997 (p. 126)
"Beef Wellington was the premier party dish of the 1960s...it was rich, dramatic, expensive, and seemed difficult and time-consuming to prepare. In short, it was everything a gourmet dish should be. In Masters of American Cookery, Betty Fussell credited beef Wellington's phenomenal popularity in the Sixties to "the discovery that anybody, with a little care, could make an edible crust."...Exactly who invented beef Wellington is not known, but there is a long Anglo-Irish-French tradition of meat cooked in pastry. Undoubtedly what we in the Unted States call beef Wellington is based on the Wellington steak of England and the steig Wellington of Ireland...In France the dish is known as filet de boeuf en croute, but whether it originated on the west of the east side of the English Channel is unkown."
---Fashionable Food: Seven Decades of Food Fads, Sylvia Lovegren [MacMillan:New York] 1995 (p. 232)
"Despite such ethnic fervor, one of the most popular dishes of the day was the very classic, very British Beef Wellington a fillet of beef tenderloin coated with pate‚ de foie gras and a duxelles of mushrooms that are then all wrapped in a puff pastry crust. Some believe that Wellington's popularity had more to do with America's competitive spirit than with any deep passion for British cuisine. It began in the '60s when couples started dabbling in a bit of culinary one-upmanship. Dinner parties with friends became elaborate as complicated recipes appeared on tables with greater regularity. Beef Wellington was considered the height of difficulty and expense because of the preparation of the puff pastry and the price of the pate‚ de foie gras. Kudos and furtive jealous glances went to the cook who mastered such a bear of a recipe. Although Beef Wellington went the way of Beef Stroganoff and Boeuf Bourguignon, it did stage a comeback in magazines such as Gourmet in the '90s, when prepackaged puff pastry and domestic foie gras made it much easier and less expense to make."
--- Leites Culinaria, Dining Through the Decades: Food of the 1970s
When did Beef Wellington become popular in the USA?
Historic newspapers confirm interest in Beef Wellington (restaurant fare, recipes, quickie home versions) peaked chic in the 1960s-1970s. Chicken Wellington was introduced in the 1970s.