The following can be found on Florida's Division of Elections Web site. It was reprinted from an essay provided by the Honorable Mary Morgan, Supervisor of Elections, Collier County, Florida, and last updated January 23, 1997:
The most often heard excuse for not voting in an election is "my one little vote won't make a difference." Yet history is full of instances proving the enormous power of one single vote. In many cases, the course of nations has been changed because one individual ballot was cast, or not cast, depending upon your point of view. Consider this …
In 1645, one vote gave Oliver Cromwell control of England.
In 1649, one vote literally cost King Charles I of England his head. The vote to behead him was 67 against and 68 for — the ax fell thanks to one vote.
In 1714, one vote placed King George I on the throne of England and restored the monarchy.
In 1776, one vote gave America the English language instead of German (at least according to folk lore.)
In 1800, the electoral college met in the respective states to cast their two votes for President. At that time, the U.S. Constitution provided the candidate receiving the most electoral votes would become President and the candidate receiving the second highest number of votes would become Vice President. When the results of the electoral college votes were opened by both houses of Congress, there was a tie vote for President between Thomas Jefferson and Aaron Burr. That threw the election of President into the House of Representatives where Thomas Jefferson was elected our third president by a one vote margin.
In 1824, none of the four Presidential candidates received an electoral majority. The election was again thrown into the House of Representatives, where John Quincy Adams defeated front runner Andrew Jackson by one vote to become the nation's 6th president. Andrew Jackson received the majority of the nation's popular vote.
In 1844, in the backwoods area of Switzerland County, Indiana on election day, a farmer named Freeman Clark lay seriously ill in bed. He begged his sons to carry him to the county seat so he could vote for David Kelso to become a state senator. David Kelso had defended old Freeman Clark on a murder charge and obtained his acquittal. The old farmer Freeman Clark got to vote for Kelso, but Clark died on his way back home. Kelso won the election by one vote. Both Freeman Clark and David Kelso were long-time Andrew Jackson supporters.
In 1844, when the new Indiana senate convened, Democrats had a majority of one counting David Kelso. At that time, state senates had the task of electing the state's United States Senator. The Indiana Senate Democrats held a caucus where it developed a majority of the party delegation favored a man who would vote against the annexation of Texas if elected to the U.S. Senate. David Kelso refused to vote for the Democratic Party choice and a deadlock resulted between the Democratic and Whig candidates. This continued for days. Finally, Kelso made his move. He proposed a new candidate: Edward A. Hannigan. In his party caucus, Kelso notified his Democratic associates he would bolt and vote with the Whigs thus electing a Whig to the Senate — unless the Democrats supported Hannigan. The Democrats felt constrained to accept Hannigan who was then elected as Indiana's U.S. Senator by one vote — that of David Kelso.