Trump cannot formally change the name of the Pentagon without Congressional approval. However, his order allows the Department of War to be used as an alternative name. The Department of War name was used in the United States for over 150 years. From 1789, after gaining independence from the British, until World War II, America had a Department of War. The department was established after President George Washington signed the document. According to Pentagon data, the Department of War oversaw the US Army, Navy, and Marine Corps. However, the Navy and Marines separated a decade later.
