Since its offcial birth on 14 June 1775 over a year before the Declaration of Independence the United States Army has played a vital role in the growth and development of the American nation. Drawing on both long-standing militia traditions and recently introduced professional standards, it won the new Republic's independence in an arduous eight-year struggle against Great Britain. At times it provided the lone symbol of nationhood around which patriots could rally. During the Civil War it preserved the Union through four years of bitter con--ict that turned brother against brother. It has repeatedly defended the United States against external threats, from the second war of independence with Great Britain in 1812 through the crusades that finally rid the world of the specters of Nazi totalitarianism, Japanese imperialism, and world communism. The defense of the nation has always been the Army's primary mission but, as this pamphlet shows, not its only one. From the beginning the Army has also been involved with internal improvements, natural disaster relief, economic assistance, domestic order, and a host of other contingencies. Although these missions may not have always been those it would have chosen for itself, our Army has drawn great satisfaction from knowing that when the nation was in need, it answered the call. This pamphlet, written by David W. Hogan, Jr., was originally produced by the Center of Military History to commemorate the 225th birthday of the United States Army.