War Department

American  

noun

U.S. History.

1. the department of the federal government that, from 1789 until 1947, was responsible for defense and the military establishment: in 1947 it became the Department of the Army, which became part of the Department of Defense when it was established in 1949.

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Example Sentences

President Abraham Lincoln spent many evenings in the War Department telegraph office reading dispatches and issuing orders.

From The Wall Street Journal • Apr. 26, 2026

“The president has made it clear that you will not have a nuclear weapon. The War Department agrees,” Hegseth said.

From Los Angeles Times • Mar. 24, 2026

The Department of Defense, now called the War Department, is investing directly in companies, demanding greater production and new technology.

From Barron's • Jan. 14, 2026

He has also reportedly called for the Defence Department to be renamed the War Department and for a 10-year ban on generals working as defence contractors after leaving the military.

From BBC • Nov. 13, 2024

It took some time to work out the details, but in December 1920, both William and Elizebeth secretly accepted positions with the War Department.

From "The Woman All Spies Fear" by Amy Butler Greenfield