This undated file photo shows the classic World War I recruiting poster created by illustrator James Montgomery Flagg. Thursday, April 6, 2017, marks the 100th anniversary of the U.S. entry into World War I, and some of the innovations that were developed or came into wide use during the conflict are still with us today, including this iconic image of Uncle Sam pointing, with the message "I WANT YOU for the U.S. ARMY." (AP Photo, File)