U.S. military operations will soon be run under the Department of War, an old name for the Department of Defense that President Donald Trump is reviving.

Trump will sign an executive order reverting to the Department of War as a secondary name for the Defense Department.

Headquartered in the Pentagon, the Defense Department has gone by its current name for decades. Here's what to know about the change.

What's the history?

Congress created the War Department in 1789, during George Washington's presidency, to oversee the Army, Navy and Marines, according to the Defense Department website. Revolutionary War commander Henry Knox served as the department's first secretary.

Oversight of the Navy was later transferred to a new Navy Department.

The War Department name was abandoned during a 1947 Cabinet reorganization under President Harry Truman. The Navy, War Department and Air Force were all moved under one department called the National Military Establishment, led by the secretary of defense. The name was changed to the Department of Defense two years later.

Why is Trump changing the name?

Trump told reporters on Aug. 25 that the old name was "stronger."

"It used to be called the Department of War, and it had a stronger sound," Trump said. "And as you know, we won World War I, we won World War II. We won everything."

The president also said that he doesn't want it to emphasize just defense.

"Defense is too defensive," he said. "We want to be defensive, but we want to be offensive, too. Seems much more appropriate.”

What are the details?

A White House summary of the order obtained by USA TODAY said the action would restore "Department of War" as a secondary name for the Defense Department. The order authorizes Hegseth to use secondary titles such as "Secretary of War," "Department of War," and "Deputy Secretary of War" in official correspondence, public communications, ceremonial contexts and non-statutory documents within the executive branch, according to the White House.

All executive departments and agencies will be required to recognize and accommodate the change to "Department of War" in internal and external communications.

Does Congress need to approve?

When Trump was asked on Aug. 25 if the name change would require an act of Congress, he suggested it may not be necessary.

“We’re just going to do it,” he said. “I’m sure Congress will go along if we need that. I don’t think we even need that.”

Yet his order, nonetheless, instructs Hegseth to recommend legislative and executive actions to "permanently rename the U.S. Department of Defense to the U.S. Department of War."

Sens. Rick Scott, R-Florida, and Mike Lee, R-Utah, filed legislation Sept. 5 to change the name. Rep. Greg Steube, R-Florida, filed a bill in the House.

Contributing: Joey Garrison, Swapna Venugopal Ramaswamy

This article originally appeared on USA TODAY: Why is Trump renaming the Defense Department? What to know about order.

Reporting by Zac Anderson, USA TODAY / USA TODAY

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