Man behind the image
Sometimes mistaken for Yankee Doodle or "Brother Jonathan," Uncle Sam is an American icon with roots that go back to the War of 1812. Was there really an Uncle Sam and if so, who was he?
Most historians admit that they are not completely certain how the character "Uncle Sam" was created, or for whom he was named (or if for anyone). However, a common theory is that Uncle Sam was named after an Upstate New Yorker, Samuel Wilson.
From meat packer ...
Samual Wilson was born in Arlington, Massachusetts, on September 13, 1766, and in 1789, he and his brother Ebenezer set out for a new life in rural Troy, New York. During the War of 1812, Wilson happened to be in the business of slaughtering and packing meat, and this is where the theory takes hold.
He provided large shipments of meat to the US Army, in barrels that were stamped with the initials "U.S." Supposedly, someone who saw the "U.S." stamp suggested -- perhaps as a joke -- that the initials stood for "Uncle Sam" Wilson. The suggestion that the meat shipments came from "Uncle Sam" led to the idea that Uncle Sam symbolized the federal government.
... To legend
Thus according to folklore, Uncle Sam was born. Uncle Sam's traditional appearance, with a white goatee and star-spangled suit, is an invention of artists and political cartoonists. According to historians, Samuel Wilson did not look like the modern image of Uncle Sam. For example, Wilson was clean-shaven, while Uncle Sam is usually portrayed with a goatee.
Purportedly, Thomas Nast, a prominent 19th-century political cartoonist, produced many of the earliest cartoons of Uncle Sam. However, some historians dispute this because Nast's drawings allegedly depicted Yankee Doodle or "Brother Jonathan," both iconic figures used to represent America in political cartoons.
Regardless of who served as the first model, the image of Uncle Sam became wildly popular in the United States and is still so today. Perhaps the single most famous portrait of Uncle Sam is the "I WANT YOU" Army recruiting poster from World War I. The poster was painted by James Montgomery Flagg in 1916-1917.
Today, with the possible exception of the Statue of Liberty, the character of Uncle Sam is probably the most easily recognizable personification of the United States of America.