No mater what a person's political views may be most can agree that the image of Uncle Sam is a well known image that represents the United States. The most iconic image of Uncle Sam is that of him pointing his finger out at the viewer stating "I want you for the U. S. Army". That image drawn by James Montgomery Flagg originally appeared on the cover of Leslie's Weeklyfor July 6, 1916 with the title of "What Are You Doing For Preparedness". This image of Uncle Sam was used to recruit troops in both World War I and World War II. But, where did the concept of Uncle Sam come from? It turns out that the notion of Uncle Sam dates back to the War of 1812 and a meat packer.
Sam Wilson was born in Massachusetts and settled in Troy New York where he and his brother Ebenezer started a meat packing business known as E & S Wilson. During the War of 1812 E. & S. Wilson acquired a contract to supply meat to the Army. Sam Wilson was know locally as "Uncle" Sam and residents of Troy assumed that the U. S. on the barrels of meat for the Army stood for "Uncle Sam" who they all knew was feeding the Army. The term Uncle Sam first appeared in print in 1813 and by 1830 there were inquires in print into the origin of Uncle Sam. Also in 1830 the new York Gazette reported on the connection between the cartoon figure and Sam Wilson.
Over the years the image of Uncle Sam changed. During the Civil War Uncle Sam acquired a beard which was associated with Abraham Lincoln. But, as stated earlier the most iconic image id that drawn by Flagg.
For more information on Uncle Sam see: http://xroads.virginia.edu/~cap/sam/sam.htm