Which document was written to define a tax base and court system for the new country?

The document that defined a tax base and court system for the new country was the Articles of Confederation. Ratified in 1781, it established a framework for the governance of the United States, outlining the powers of the national government, including taxation and the establishment of courts. However, its weaknesses, particularly in federal taxation and judicial authority, led to the eventual drafting of the U.S. Constitution in 1787.