The significant historical document passed at the Constitutional Convention in 1787 was the United States Constitution. This foundational document established the framework for the federal government and delineated the separation of powers among the executive, legislative, and judicial branches. It incorporated a system of checks and balances to prevent any one branch from becoming too powerful. Additionally, the Constitution set forth principles like popular sovereignty and limited government. Its ratification in 1788 marked a pivotal moment in American history, creating a blueprint for governance that greatly influenced democratic movements worldwide.