In 1845, Texas was admitted to the union as a state by one vote — that of Edward A. Hannigan from Indiana. The 1844 and 1845 excerpts on the series of single votes leading to Texas statehood are from the book Magnificent Destiny.
In 1846, a one vote margin in the U.S. Senate approved President Polk's request for a Declaration of War against Mexico.
In 1850, California was admitted to the union by a margin of one vote.
In 1859, Oregon was admitted to the union by a margin of one vote.
In 1867, The Alaska Purchase was ratified by just one vote paving the way for the eventual admission of America's largest state in 1958.
In 1868, one vote in the U.S. Senate saved President Andrew Johnson from impeachment.
In 1875, a one vote margin changed France from a monarchy to a republic.
In 1875, Florida's U.S. Senators were still elected by the state legislature. Democrat Charles W. Jones of Pensacola was elected to the U.S. Senate by a majority of one vote.
In 1876, no presidential contender received a majority of electoral votes so the determination of the country's president was again thrown into the U.S. House of Representatives. By a one vote margin, Rutherford B. Hayes became the new U.S. president. When Tilden's party protested the tabulation and demanded a recount, Congress established a 15-member electoral commission to again count the electoral votes and declare the result. By an eight to seven margin — again, one vote — the commission affirmed the count and gave the election and presidency to Hayes.
In 1885, two members of the Florida House of Representatives waged a friendly but close contest for Speaker of the House. Robert W. Davis of Green Cove Springs defeated Gen. Ernest Yonge of Pensacola by one vote.
In 1889, by a one vote margin, Washington was admitted to statehood with the union.
In 1890, by a one vote margin, Idaho became a state.
In 1916, if presidential hopeful Charles E. Hughes had receive one additional vote in each of California's precincts, he would have defeated President Woodrow Wilson's re-election bid.
On November 8, 1923, members of the then recently — formed revolutionary political party met to elect a leader in a Munich, Germany beer hall. By a majority of one vote they chose an ex-soldier named Adolph Hitler to become the Nazi Party leader.
In 1940, the vote taken by the French parliament to maintain its status as a republic failed by a margin of one vote.
In 1941, the Selective Service Act (the draft) was saved by a one vote margin — just weeks before Pearl Harbor was attacked.
In 1948, a Texas convention voted for Lyndon B. Johnson over ex-Governor Coke Stevens in a contested Senatorial election. Lyndon Johnson because U.S. Senator by a one vote margin.
In 1948, if Thomas E. Dewey had gotten one vote more per precinct in Ohio and California, the presidential election would have been thrown into the U.S. House of Representatives where Dewey enjoyed more support than his rival — incumbent Harry Truman. As it was, Dewey was expected to win the general election by a landslide so most Republicans stayed home. Only 51.5 percent of the electorate voted. Truman defeated Dewey.
In a 1955 city election in Huron, Ohio, the mayor was elected to office by one vote.
In a 1959 city election, mayors of both Rose Creek and Odin, Minnesota were elected to their respective offices by one vote.