9781422280188

Union Soldiers entrenched in the Battle of Chancellorsville.

The 20th Century The first half of the 20th century saw steady changes in the U.S. Army. During the first two decades, its soldiers benefited from major leaps in military technology, including magazine rifles, machine guns, radio communications, new artillery, and the advent of military aviation. Officer-training schools grew in number, producing more men competent for leadership. Total soldier numbers grew to around 100,000 men by 1905 alone. Even so, the Army did not ap- proach the scale of the major European armies, which were to face each other in World War I (1914–1918). The United States did not enter the war until 1917, but even as battle lines were being drawn across Europe, the U.S. government realized the importance of a large army. The Na- tional Defense Act of 1916 authorized the Army to expand to 175,000 men in 111 regiments.

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