"Uncle Sam" Came From the War of 1812

From Task & Purpose "How Uncle Sam Became An American Icon" by Sarah Sicard.

In a widely accepted story, in 1813, a man from Troy, New York, Samuel Wilson, worked as a meat packer/distributor of beef for the U.S. Army.  When the meat was packaged in barrels, he would stamp "U.S." on the barrel for "United States."

Soldiers, however began referring to the beef as "Uncle Sam's" and it stuck as a nickname for the federal government.

--Brock-Perry