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 told reporters Tuesday in the Oval Office.

From Los Angeles Times • Mar. 25, 2026

“The first sinking of an enemy ship by a torpedo since World War II. Like in that war back when we were still the War Department, we are fighting to win.”

From Barron's • Mar. 6, 2026

He reverses a post-World War II decision that renamed the War Department the Department of Defense, returning its meaning to “war.”

From Salon • Nov. 8, 2025

Would William take a civilian job with the War Department instead?

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