Which document created the first three-branch federal government of the United States?

The United States Constitution created the first three-branch federal government of the United States.

The Constitution established legislative, executive, and judicial branches. Congress received legislative authority, the president headed the executive branch, and the federal courts exercised judicial power. This structure was designed to divide authority and create checks among the branches.

Delegates drafted the Constitution during the Philadelphia Convention in 1787. The document replaced the Articles of Confederation, which had created a weaker central government and lacked a separate executive branch. The Constitution was signed on September 17, 1787, and took effect after the required states ratified it.

The first ten amendments, known as the Bill of Rights, were added in 1791. They protect liberties such as freedom of speech and religion, but they did not create the three branches. The Constitution’s basic framework remains the foundation of the U.S. federal government.