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.

---

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 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

In the end, the president will get his War Department.

From Salon • Sep. 11, 2025

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

But he was met at the train and taken over to the War Department.

From "Cheaper by the Dozen" by Frank B. Gilbreth Jr. and Ernestine Gilbreth Carey