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

When asked to comment, Pentagon spokesman Sean Parnell said in a statement: “It is the duty of the War Department to ensure that the commander-in-chief has every possible military option at his disposal.”

From The Wall Street Journal • Apr. 4, 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 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

They came not only from the War Department, but also from the Navy, the State Department, the Justice Department, and even the post office.

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