Kennedy's campaign gained momentum after the first debate, and he pulled slightly ahead of Nixon in most polls. On Election Day, Kennedy defeated Nixon in one of the closest presidential elections of the 20th century. In the national popular vote, by most accounts, Kennedy led Nixon by just two-tenths of one percent (49.7% to 49.5%), while in the Electoral College, he won 303 votes to Nixon's 219 (269 were needed to win). Fourteen electors from Mississippi and Alabama refused to support Kennedy because of his support for the civil rights movement; they voted for Senator Harry F. Byrd of Virginia, as did an elector from Oklahoma. Kennedy became the youngest person (43) ever elected to the presidency, though Theodore Roosevelt was a year younger at 42 when he automatically assumed the office after the assassination of William McKinley in 1901.