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 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

The Pentagon - which oversees the US armed services - is the successor to the War Department, which was first established as a cabinet-level agency in 1789 and existed until 1947.

From BBC • Sep. 4, 2025

The War Department was in charge of all the camps at this point.

From "Farewell to Manzanar" by Jeanne Houston