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. Unlike most college-bound Virginians of his day, Madison did not attend the College of William and Mary, where the lowland Williamsburg climate - thought to be more likely to harbor infectious disease - might have strained his delicate health. Biographer Terence Ball says that at Princeton: On September 15, 1794, Madison married Dolley Payne Todd, a 26-year-old widow, previously wife of John Todd, a Quaker farmer who died during a yellow fever epidemic in Philadelphia. Aaron Burr introduced Madison to her, at his request, after Dolley had stayed in the same boardinghouse as Burr in Philadelphia. After an arranged meeting in spring 1794, the two quickly became romantically engaged and prepared for a wedding that summer, but Dolley suffered recurring illnesses because of her exposure to yellow fever in Philadelphia. They eventually traveled to Harewood, Virginia for their wedding.