Although Uncle Sam is one of our most familiar icons, many Americans have little or no concept of his origins.
The origins of Uncle Sam can be traced well back into colonial times. The actual figure of Uncle Sam, however, dates from the War of 1812, and like many mythological and symbolic figures, Uncle Sam has origins in actual fact and, in this case, an actual man. Born in Massachusetts, Samuel Wilson settled in the town of Troy, New York. Known locally as "Uncle" Sam, he would be the impetus for a regional saying which would eventually become a national icon.
Uncle Sam Wilson moved to Troy with his brother, Ebenezer, with whom he later began the firm of E. & S. Wilson. It was through this firm, and the war contracts they acquired in 1812, that Sam gained his notoriety. One such contract was for the supply of meats to the Army. Troy residents associated the "U.S." on the sides of the barrels of troop rations with "Uncle Sam."
By the early twentieth century, there was little physical resemblance left between Samuel Wilson and Uncle Sam. The Civil War saw a major transition in the development of Uncle Sam as his image was associated with that of Abraham Lincoln. It was during this period that Sam aged and acquired a beard. The final version of Uncle Sam that we are most familiar with today came about in 1917. The famous "I Want You" recruiting poster by James Montgomery Flagg set the image of Uncle Sam firmly into American consciousness.
(Adapted from the American Studies at the University of Virginia)