Uncle Sam is probably based on Samuel Wilson, who was a resident of Troy, NY.
"At the time of the War of 1812, Samuel Wilson was a prosperous middle-aged meat-packer in Troy. He obtained a contract to supply beef to the Army in its campaign further north, which he shipped in barrels. The barrels, being government property, were branded with the initials "U.S.", but the teamsters and soldiers would joke that the initials referred to "Uncle Sam", who supplied the product. Over time, it is believed, anything marked with the same initials (as much Army property was) also became linked with his name."
And then he died and was buried in Troy, I guess.
It's sort of sad that our big patriot was just some guy with a meat contract.
(Uncle Sam want you! to buy some steak from him.)