James Montgomery Flagg (1877-1960) was an American artist and illustrator best known for creating the iconic "I Want YOU for U.S. Army" Uncle Sam recruitment poster during World War I. A child prodigy, he began his professional career at age 12, selling his first illustration to St. Nicholas Magazine. He went on to create numerous magazine covers, advertisements, and political posters. His distinctive style combined bold imagery with masterful draftsmanship. For the famous Uncle Sam poster, Flagg used himself as the model, adapting the British Lord Kitchener recruitment poster design. Over his lifetime, he created thousands of illustrations for top publications like Life, Judge, and Collier's.