 Nearly 2.7 million men and women who served in the U.S. military during an official period of conflict are members, making The American Legion the nation's largest veterans groups, with approximately 14,500 American Legion Posts worldwide.The American Legion Auxiliary is the largest patriotic women's service organization in the world, with nearly 1 million members.Affiliated with The American Legion and chartered by Congress in 1920, the Auxiliary is a veterans' service organization with members in nearly 10,000 American communities.