In 1933, with passage of the National Guard Mobilization Act, Congress finalized the split between the National Guard and the traditional state militias by mandating that all federally funded soldiers take a dual enlistment/commission and thus enter both the state National Guard and the National Guard of the United States, a newly created federal reserve force. The National Defense Act of 1947 created the Air Force as a separate branch of the Armed Forces and concurrently created the Air National Guard of the United States as one of its reserve components, mirroring the Army's structure.