Which document established the government of the United States?

The U.S. Constitution is the foundational document that established the government of the United States. It articulates the structure, powers, and limitations of the government, and serves as the supreme law of the land. Drafted in 1787 and ratified in 1788, the Constitution lays out the framework for the three branches of government: the legislative, executive, and judicial branches. It also delineates the separation of powers and the system of checks and balances designed to prevent any one branch from becoming too powerful.

In contrast, the Declaration of Independence asserted the colonies' intention to separate from British rule and is not a governing document. The Articles of Confederation were the first attempt at a governing framework, but they created a weak central government that ultimately proved ineffective, leading to the drafting of the Constitution. The Bill of Rights, which consists of the first ten amendments to the Constitution, primarily focuses on the protection of individual liberties and does not establish government structure. Thus, the U.S. Constitution is the correct answer as it is the key document that officially organized and defined the United States government.