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  Welcome to the Department of Defense

With our military units tracing their roots to pre-Revolutionary times, you might say that we are America’s oldest company. And if you look at us in business terms, many would say we are not only America’s largest company, but its busiest and most successful.

How We Evolved

The Army, Navy, and Marine Corps were established in 1775, in concurrence with the American Revolution. The War Department was established in 1789, and was the precursor to what is now the Department of Defense.

The Department of the Navy, was founded in 1798.

The Coast Guard (part of Homeland Security in peacetime), can trace it's history back to 1790.

Congress, in 1947, established a civilian, Cabinet-level Secretary of Defense to oversee an also newly created National Military Establishment.

The U.S. Air Force was also created, along with a new Department of the Air Force. The War Department was converted to the Department of the Army.

Finally, the three services, Army, Navy, and Air Force, were placed under the direct control of the new Secretary of Defense.

In 1949, an amendment to the Act consolidated further the national defense structure, creating what we now know as the Department of Defense, and withdrawing cabinet-level status for the three Service secretaries. 

5 Million Strong

With over 1.3 million men and women on active duty, and 669,281 civilian personnel, we are the nation's largest employer. Another 1.1 million serve in the National Guard and Reserve forces. About 2 million military retirees and their family members receive benefits. MORE

Source: DMDC

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