The 1917 poster of Uncle Sam recruiting for the U.S. Army is one of the most iconic American images, but its design and concepts are actually British in origin.
James Montgomery Flagg, I Want You for U.S. Army, 1917
The design and “want you” concept come from the 1914 poster featuring the British Secretary of State for War, Lord Kitchener:
Alfred Leete, Lord Kitchener Wants You, 1914
As for Uncle Sam, the symbol of the U.S., he is modeled on John Bull, who has been the personification of England since John Arbuthnot’s The History of John Bull, published in 1712. John Bull eventually became the symbol of the UK and was famously used in war recruiting posters:
British Government, John Bull Recruiting Poster, 1915
Combine the designs and concepts of these two posters, and you get Uncle Sam’s I Want You for U.S. Army.
That’s the inspiration for the most iconic recruiting poster ever.