Mushroom ketchup was a popular dish among 18th century troops. It is a ketchup prepared with mushrooms instead of tomatoes, and it was very popular in the UK. Since the American colonies were still a part of Britain when George Washington was probably introduced to it, so it must have been introduced to the colonies through Britain.

Fredrick II was a great general and the patron of the arts. Known as Fredrick the Great (and he had a fascinating rivalry with Empress Maria Theresa of Austria, which you can read about in In the Shadow of the Empress by Nancy Goldstone). Because Fredrick was a cultured man, his favorite food was a delicacy of the time: candied violets. It's certainly not something you would expect when looking at the general's long military career, but it does show his love for art and culture!

King Henry I, who is known for helping foster peace in England during his reign, loved lamprey. Lamprey is a jawless fish that resemble eels. However, his favorite food ended up being what killed him. Despite the doctor warning Henry that he shouldn't gorge on the "delicacy" anymore, he did anyways and died of foodborne illness.

Doesn't Abraham Lincoln's favorite food being apples make sense? The famous president would usually eat apples with milk or in a tart/pie. The apples make sense because Lincoln really was a modest man who tried to help his country. Luckily, this was not a deadly delicacy (unlike Henry).

Winston Churchill's favorite food was... turtle soup? He allegedly brought it on his travels and even served it to President Roosevelt. The dish was very popular in the times of WW2, but Churchill apparently picked it up in WW1.

Maria Theresa loved Viennese coffee, which was eventually known as Cafe Maria Theresa after her. It is a double espresso served with orange liqueur and topped with whipped cream. It originated in Austrian coffee houses. Maria Theresa was associated with coffee culture, so this makes sense.

Napoleon actually fought in the Battle of Marengo, so it is probably where he picked up his favorite food. He ate it as a celebration of his victory in the battle. Half Italian and half French, the dish is skin-on, bone-in chicken thighs with garlic and tomatoes.

Helen Keller was obsessed with hot dogs, and I don't say that lightly. Her secretary actually had to make sure that none were in the house because she was worried that that was all her mistress would eat. However, after her secretary passed away, Keller would enjoy as many hot dogs as she liked. Keller's love of hot dogs probably came from her childhood, since the smell was one of the first ones she recognized.

Jane Austen had an extremely relatable favorite food: Toasted cheese! She specifically liked it sandwiched between lightly buttered bread. Austen even wrote in letters to her sister about her toasted cheese obsession (which is, again, relatable). 

Queen Victoria loved to have this cake with her tea. It actually was named after her because of how fond she was of it. Actually, Victoria's endorsement of the dessert allowed it to become one of the most prominent teatime traditions. The perks of being a monarch are you get your favorite foods named after you and you set a precedent for others to enjoy it.