Madison's presidency, by treaty or war, added 23 million acres of American Indian land to the United States. He retired from public office in 1817 and died in 1836. Madison was never able to privately reconcile his Republican beliefs and his slave ownership. During his time at Princeton, his closest friend was future Attorney General William Bradford. Biographer Terence Ball says that at Princeton: Before a quorum was reached at the Philadelphia Convention on May 25, 1787, Madison worked with other members of the Virginia delegation, especially Edmund Randolph and George Mason, to create and present the Virginia Plan. The Virginia Plan was an outline for a new federal constitution; it called for three branches of government (legislative, executive, and judicial), a bicameral Congress (consisting of the United States Senate and the United States House of Representatives) apportioned by population, and a federal Council of Revision that would have the right to veto laws passed by Congress.