What changes occurred in the US military during the period of the First World War?

During the First World War, the US military underwent significant expansion, modernisation, and organisational changes.

At the onset of the First World War, the United States military was relatively small and ill-prepared for a large-scale conflict. However, the entry of the US into the war in 1917 led to a rapid and significant expansion of the military. The Selective Service Act of 1917 authorised the federal government to raise a national army through conscription, leading to the induction of nearly 2.8 million men into the military. This represented a dramatic increase in the size of the US military, which had numbered less than 200,000 before the war.

In addition to the expansion in size, the US military also underwent significant modernisation during the First World War. The war marked the first large-scale use of new military technologies such as tanks, airplanes, and submarines by the US military. The US Army Air Service, the precursor to the US Air Force, was established in 1918 and played a crucial role in the war. The use of these new technologies required the development of new tactics and strategies, leading to significant changes in the way the US military conducted warfare.

The First World War also brought about significant organisational changes within the US military. The War Department underwent a major reorganisation in 1918 to better manage the expanded and modernised military. The General Staff was strengthened and the roles of the various branches of the military were more clearly defined. The war also led to the creation of new agencies such as the Chemical Warfare Service and the Tank Corps.

Furthermore, the war led to changes in the social composition of the US military. African Americans, who had previously been largely excluded from the military, were drafted in large numbers and served in segregated units. Women also served in the military for the first time in non-combat roles, primarily as nurses.

In conclusion, the First World War brought about significant changes in the US military, including a dramatic expansion in size, the adoption of new technologies, organisational changes, and changes in the social composition of the military.