In which country was the Caesar salad invented?

Answer

Caesar Cardini created it in Tijuana in the 1920s. It is not named for Julius Caesar.

Context

Britannica credits Cesare Cardini, an Italian-born restaurateur, with creating the salad in 1924 at his restaurant Caesar's in Tijuana, Mexico. Cardini had been running restaurants in San Diego, and he moved operations across the border during Prohibition, when Americans crossed into Tijuana for food and drink. The restaurant later moved to a hotel a few blocks away and closed in 2009, according to the same account.

The recipe in its published form is simple: romaine lettuce, garlic-flavored olive oil, coddled egg, lemon juice, Worcestershire sauce, Parmesan, salt, pepper and croutons. The published recipe was released in 1986 by Rosa Cardini, Cesare's daughter. Tableside preparation is a hallmark of the dish. Britannica says Cardini moved to Los Angeles in 1935, where he sold and trademarked a salad dressing.

Several points are contested. A frequent claim says the salad contained anchovies from the start; in the family's account, the anchovy flavor came from Worcestershire sauce, though other cooks have added anchovies. Some stories credit Cesare's brother Alex with the invention, and some say the dish was improvised on a busy holiday weekend with whatever was in the kitchen. These competing accounts come from different sources and cannot all be resolved from the historical record. What is well established is the Tijuana setting. The name refers to Cesare Cardini, not to Julius Caesar, a mix-up that is common among people who assume it is a Roman recipe.