The American document that outlined the separation of powers and the federal system is the Constitution of the United States. Ratified in 1788, the Constitution established the framework of the American government by delineating the roles and responsibilities of the three branches: the executive, legislative, and judicial. This separation of powers is designed to prevent any one branch from becoming too powerful, ensuring a system of checks and balances. Additionally, the Constitution laid the groundwork for federalism, distributing authority between the national and state governments. Overall, it remains a foundational text for American democracy and governance.