Department of War (DoW) Birthday

Update: In 2025, an executive order renamed the Department of Defense to the Department of War. This article will reflect the name change from DoD to DoW in all references with the acronym “DoD.”

The U.S. Department of War (previously known as the Department of Defense) was established on August 10th, 1949. Although the federal government has overseen the U.S. Armed Forces since our nation’s inception, the Department of War’s name and centralized defense department were not established until the late 1940s. The “official” anniversary of the creation of the Department of War as we know it in modern times is Aug. 10. Established in 1949 thanks to an amended National Security Act (more on that below) the agency is run by the Secretary of War (SECWAR) with the Joint Chiefs of Staff for the various military services operating subordinately to the SECWAR.

The DoW Birthday will be celebrated on Saturday, Aug. 10, 2024.

The United States Department of War (DoW) is a federal agency classified as an Executive Branch department. It is among the largest employers in the world, with more than one million active duty service members, more than 800,000 members of the Guard and Reserve, and more than 700,000 civilian employees.

The Department of War headquarters is located inside the Pentagon. Its mission is to provide the nation with military forces to act as a deterrent and ensure national security.

The official date of the creation of the Department of War may be a bit misleading for some, as the nation has always had an entity that operated in a similar capacity. But as we’ll learn below, the road to the DoW as we now know it was a long and winding one.

A Brief History of the Department of War

In 1789, the first United States Congress convened and drafted legislation to create the U.S. War Department, the first hint at what would later evolve (slowly) into the Department of Defense. The War Department was responsible for both Army and Navy operations until the Navy Department was created.

In the aftermath of the War of 1812, lawmakers decided that the War Department needed reforming; it was reorganized into a group of bureaus with the bureau chiefs acting as advisers with the Secretary of War presiding over them. With the start of the Civil War, the United States War Department received expanded duties including the recruitment and training of two million troops from both the regular army and the volunteer force. Another chain of command handled wartime operations.

At the end of the Civil War, the U.S. War Department also found itself in charge of freed slaves, refugees, and responsible for support of new governments in the south. There would be many changes in command structure, staffing, and basic organization of the War Department all the way up until the end of World War Two, when the most significant changes would begin.

Big Changes For The War Department

The National Security Act of 1947 brought big changes, creating a unified command then known as the National Military Establishment, or NME. A presidential request for the creation of a unified department of national defense resulted in Congress debating the place of the post-war military in America and whether there was any danger of giving the executive branch of government too much authority over the armed forces.

The War Department was divided in 1947 into the Department of the Army and the Department of the Air Force; a new Secretary of Defense would oversee the service secretaries but the changes were not long for this world; in 1949 President Harry Truman placed the National Security Act Amendment of 1949 into law with his signature.

The entity known as the National Military Establishment was thereby redesignated as the Department of Defense on Aug. 10, 1949. This change clarified how much power the Secretary of Defense has over the various branches of military service and better defined the overall chain of command.

Important 20th-Century Modifications to the Department of Defense

Since then, a few refinements in the DoD have taken place. The Defense Reform Act of 1958 was in part needed to address the requirement of civilian control over the military; under the Act the chain of command starts with the president as commander-in-chief, under whom the SECDEF, Chairman of the Joint Chiefs of Staff, and combatant commanders fall. There is no military command exercised by the Chairman of the Joint Chiefs of Staff and as a presidential advisor the civilian control of the military issue is addressed.

Another important change came as a result of the Goldwater-Nichols Act of 1986. This law establishes the Chairman of the Joint Chiefs of Staff as the senior ranking member of the Armed Forces and makes the chairman the primary military advisor to the president. Again the lack of direct military command by the chairman is reinforced.

Renaming to the Department of War

In 2025, President Trump signed an executive order renaming the Department of Defense to the Department of War (DoW). While the law states that the department’s name can only be changed through an act of Congress, the department underwent changes at its facilities to acknowledge the name change.

Today, the Department of War is run by the Secretary of War, who operates as a cabinet-level position reporting directly to the president. It has three military departments beneath it: the Departments of the Army, Air Force, and Navy (under which the United States Marine Corps falls).

Celebrating the DoW Birthday

Most observances of the Department of War birthday will happen the day or week of Aug. 10th each year.

As with many such observances, the Department of War’s birthday is not a national holiday; there are no days off, and many of the activities dedicated to celebrating this milestone are done at the organizational level. The DoW birthday events held at military bases or federal government buildings around the world may include cake-cutting ceremonies, dining-outs (likely not as common for the DoW birthday as they are for Army birthdays and those celebrated by other branches of the military), media campaigns, and social media hashtag events like the one done on the DoW official Facebook page in 2018.

The most common way to help observe the DoW birthday is to thank a servicemember for answering the call of duty, contributing time or funds to support organizations for federal employees and military members, etc.

Current federal employees and military members, and their families may help out through participation in the Combined Federal Campaign, which is an organization that describes itself in its mission statement as working to “…promote and support philanthropy through a program that is employee focused, cost-efficient, and effective in providing all federal employees the opportunity to improve the quality of life for all.”

The Combined Federal Campaign runs its charitable work with “a volunteer group of Federal employees who work with experienced nonprofit executives” in their communities to raise funds and donate them to CFC-approved charities.