The Constitutional Convention was held in Philadelphia in 1787 to address issues with the Articles of Confederation. Delegates debated plans like the Virginia Plan and New Jersey Plan before agreeing to the Great Compromise, which established a bicameral legislature with representation based on population in the House and equal representation of states in the Senate. The Convention also compromised on counting slaves for representation and continuing the international slave trade. The resulting Constitution established a representative democratic republic with separation of powers and checks and balances between the three branches of government. It was ratified by nine states and went into effect in 1788.