The U.S. Army Prior to World War I

After the United States entered the First World War on April 6, 1917, they were woefully unprepared to fight a modern conflict against major imperial powers. Though the National Defense Act of 1916 had authorized the expansion of both the Regular Army and National Guard, these were slowly implemented. When the United States entered the war in April 1917, these expansions had not fully taken effect, and they could only field an army of around 600,000 men between the Army, Marines, and National Guard.1

Branch of ServiceApproximate Number of Men
Army (Active Duty)120,000
Army (Reserve)80,000
Marine Corps7,000
National Guard380,000
A chart showing the approximate breakdown of United States manpower in April 1917.2

The Regular Army was a peacetime army, with aging company officers who had a strong affinity for drinking and reminiscing about past exploits. Senior officers had little to no experience commanding troops during a major war, since the U.S. Army had focused on smaller conflicts. These included fighting groups of Native Americans in the West, suppressing Moro guerrillas in the Philippines, and chasing Mexican revolutionary Pancho Villa. The U.S. had fought the Spanish in 1898, but that conflict lasted only a few months. Additionally, training in the years leading up to the First World War was inadequate, with no major technical training programs or instruction about combined arms operations, an essential component of First World War strategy and tactics.3

American troops around an artillery piece in the Philippines, circa 1899. Source: Library of Congress.

The US War Department had two major problems to solve once it entered World War I: manpower and training.

Training for War

Notes:

  1. Geoffrey Wawro, Sons of Freedom: The Forgotten American Soldiers Who Defeated Germany in World War I (New York: Basic Books, 2018), 54–55.
  2. Geoffrey Wawro, Sons of Freedom: The Forgotten American Soldiers Who Defeated Germany in World War I (New York: Basic Books, 2018), 54–55.
  3. Wawro, Sons of Freedom: The Forgotten American Soldiers Who Defeated Germany in World War I, 55. Combined arms operations refers to the coordination between various types of military forces. During the First World War, the forces typically involved in combined arms operations were infantry, artillery, tanks, and air power.