Today's learning is actually more of a slap in my head. For some reason, I always thought Uncle Sam wasn't real. Honestly. I thought he was just a famous war propaganda or something like that. I'm ashamed of my huge stupidity in this case!
Turns out that Uncle Sam's actual name was Samuel Wilson, a meat dealer for the United States army during the Anglo-American war, in 1812. The barrels that carried the meat sent to the soldiers were branded "U" and "S", as in United States and the men, as a joke, began to say it meant "Uncle Sam". The troop, which fought in northern New York, soon adopted the "Uncle" as the responsible for the food.
In 1870, the cartoonist Thomas Nast turned the famous icon into a portrait, which is most famous for its use in the World War 1 (1914-1918) posters, encouraging young men to enlist for the US army. In 1961, the United States Congress oficially adopted "Sam" as a national symbol.