The figure “Brother Jonathan” personified the United States during the Revolutionary War, but during the War of 1812, his successor—“Uncle Sam”—was invented.
The moniker “Uncle Sam” was probably coined in reference to businessman Sam Wilson, who supplied American troops along the Canadian border with barrels of meat stamped with “U.S.” This, of course, stood for “United States,” but soldiers joked that the rations were from “Uncle Sam.” The term became popular in reference to supplies or gifts from the government, but it was just a name.
A visual representation of Uncle Sam didn’t appear until 1832. His image evolved over the next 30 years. Uncle Sam and Brother Jonathan were both popular icons through the Civil War, but eventually Uncle Sam incorporated traits from Brother Jonathan—and President Abraham Lincoln—to become the dominant icon. By the late 1850s, Americans knew Uncle Sam as a serious, grandfatherly man with a white beard who dressed in red, white, and blue stripes and a top hat.
The best-known portrait of Uncle Sam appeared on World War I military recruitment posters, which featured him pointing his finger directly at young men and saying “I want you.”
Read more about the symbols coming out of the War of 1812: