This is a list of notable cases of electoral fraud in the United States, including elections that were overturned by the United States Congress due to allegations of electoral fraud. The list features instances of voter and ballot fraud, as well as elections where the results were altered by other illegal actions related to the voting process. It does not include cases that are limited to campaign finance violations, defined as a separate category of election crime by the United States government.
1780s A 1916 investigation by Harvard historian Samuel Eliot Morison found that vote totals in the Massachusetts Constitutional Convention of 1779–1780 had been manufactured, and that the Constitution had not in fact been ratified by the required two thirds of voters.
1840s In the 1844 United States presidential election in Louisiana, Democrat James K. Polk won over Whig Henry Clay by 699 votes. The victory was due to Polk's fraudulent 990-vote margin in Plaquemines Parish, where he obtained 1,007 votes compared to just 17 for Clay. There were only 538 total eligible voters in the parish as of 1840, and only 250 people total had voted in the 1840 election.
1850s In the 1854–1857 Kansas Territory elections, pro-slavery forces carried out voter fraud on multiple occasions, including by importing pro-slavery people from Missouri to cast ballots. The 1854 United States House of Representatives election in Kansas Territory results were vacated by Congress in 1856 due to a significant number of illegal votes causing the election of pro-slavery John Wilkins Whitfield. The 1855 and 1857 Kansas territorial legislature elections were impacted by significant electoral fraud. The 1857 election was annulled by Governor Robert J. Walker, with Walker instead certifying the election of anti-slavery Free-Stater candidates. Mass voter fraud also affected a 1857 referendum ratifying the pro-slavery Lecompton Constitution. In a subsequent 1858 referendum, the Lecompton Constitution was defeated by a wide margin.
In the 1855 Wisconsin gubernatorial election, the Wisconsin Supreme Court overturned the victory of incumbent Democrat William A. Barstow over Republican Coles Bashford due to fraud, which included results being canvassed from townships where nobody lived.
In the 1855 United States House of Representatives election in New Mexico Territory, José Manuel Gallegos defeated Miguel Antonio Otero by 99 votes. Significant irregularities were revealed, including that Gallegos, a Catholic priest, had rounded up underage boys to vote and swear they were eligible, with the promise that he would absolve them of their sins. Otero successfully contested the election.
In the 1857 Minnesota gubernatorial election, the Minnesota Democratic Party won by utilizing falsified results supplied by the party-owned Dakota Land Company, which reported 99.1% of votes delivered to be for the Democratic candidate, Henry Sibley.
In the 1850s, Know Nothing Party officials rigged elections in cities such as Louisville, Kentucky, New Orleans, Louisiana and Baltimore, Maryland through methods that included taking control of voting wards, stealing ballot boxes and violently intimidating immigrant voters.
1860s In the 1860 United States presidential election in New York, the Democratic Tammany Hall machine committed voter fraud against Republican nominee Abraham Lincoln, with significant portions of registered voters in some New York City wards being fake. Lincoln nonetheless won the state. Fraud also occurred in New Jersey, Pennsylvania and Rhode Island. In the 1864 United States presidential election in New York, seven agents appointed by New York governor Horatio Seymour to collect votes from soldiers were arrested for impersonating military officers and forging soldier names and signatures in order to illegally record their votes. In the 1868 United States presidential election, violence by white Democrats against Black Republicans in Louisiana and Georgia severely decreased the number of votes received by Republican nominee Ulysses S. Grant, to the point where he received zero votes in St. Landry Parish, Louisiana despite the Republican gubernatorial candidate earlier that year receiving 2,500 votes. The Louisiana State Legislature voted to invalidate the state's electoral votes as a result. In the 1868 United States presidential election in New York, Tammany Hall machine boss William M. Tweed admitted the organization had purposefully caused the election returns from New York City to be delayed in order for them to overcome the totals from upstate. Tammany Hall also naturalized 65,000 people in courtrooms they controlled in the months prior in order to get them to vote.
1870s In the 1870 United States House of Representatives elections in Arkansas, John Edwards won in the 3rd district, but was removed after a congressional investigation found that fraudulent votes had caused his victory over challenger Thomas Boles. In the 1876 United States presidential election between Republican Rutherford B. Hayes and Democrat Samuel J. Tilden, voter fraud was widespread on both sides, with South Carolina notably reporting an impossible 101 percent turnout. Violence and intimidation against Black Republican voters also occurred in Southern states. In four contested states, Republicans and Democrats filed separate tallies favoring their respective candidates. The election was bitterly contested and ultimately decided by the Congress-appointed Electoral Commission in favor of Hayes.
1880s In the 1880 United States House of Representatives elections in South Carolina, 5th district challenger Robert Smalls successfully contested the election of incumbent George D. Tillman, which was marked by voter fraud as well as voter intimidation. Tillman won the seat back in 1882 using similar tactics, and remained in office. In the 1884 United States House of Representatives election in New Mexico Territory, Tranquilino Luna defeated Francisco A. Manzanares due to fraud, which included him winning Valencia County 4,279 to 0, and significant "alphabetical voting", where returns were falsified based on the alphabetical registry list. The seat was subsequently awarded to Manznares. In the 1888 United States presidential election, there was evidence of voter fraud in some states that favored Republican Benjamin Harrison, particularly in his home state of Indiana. Public backlash contributed to the nationwide implementation of secret ballots. In the 1888 United States House of Representatives elections in Arkansas, John M. Clayton lost to Clifton R. Breckinridge in the 2nd district by 846 votes after a ballot box with a large majority of Clayton votes was stolen. Clayton was assassinated the following year while challenging the election, but was posthumously declared the winner by Congress. In the 1888 United States House of Representatives elections in Maryland, Barnes Compton was initially elected in the 5th district, but his opponent Sydney E. Mudd successfully contested the election the following year due to fraud.
1890s In the 1892 Alabama gubernatorial election, evidence suggests that Reuben Kolb's loss to incumbent Thomas Goode Jones was decided by fraud. This included ballot boxes being stolen, votes being swayed by bribery or threats, and counties in the Black Belt announcing results before later changing them. Kolb was not allowed by law to contest the results, and lost the gubernatorial race in 1894 under similar circumstances. In the 1896 Texas Legislature election, an African-American candidate elected in a Robertson County district despite stolen ballot boxes and voter intimidation was not declared the winner by election officials, and when he threatened to contest the election he was shot in the arm by County Judge O.D. Cannon. In the 1898 North Carolina elections, voter fraud and intimidation contributed to Democratic victories across the state. In the 9th district congressional race, Republican Richmond Pearson successfully contested the victory of Democrat William T. Crawford.
1900s In the Alabama Constitution of 1901 ratification referendum, widespread electoral fraud in the Black Belt caused the ratification to pass. The constitution remained in effect until 2022. In the 1905 Louisville mayoral election, the victory of Paul C. Barth over Joseph T. O'Neal Sr. was annulled in 1907 by the Kentucky Court of Appeals due to evidence of illegal voter registration, ballot tampering and voter intimidation. – Scholar search In the 1905 New York City mayoral election, there was voter fraud against William Randolph Hearst linked to the Tammany Hall machine. Hearst lost to George B. McClellan Jr. by 3,472 votes. In the 1909 United States Senate election in Illinois, William Lorimer was elected by state legislators, but the Senate determined he had engaged in vote buying and voted to expel him in 1912.
1910s In the 1910 Adams County, Ohio elections, vote buying was rampant to the extent that judge Albion Z. Blair disenfranchised nearly 1,700 voters – a quarter of the electorate – as a penalty for their participation. In a 1914 Terre Haute, Indiana local election, a federal court found mayor Donn M. Roberts and several other local government officials guilty of conspiracy to corrupt the election. It was notable as one of the first cases where a federal court had jurisdiction over local elections. In the 1918 United States House of Representatives elections in Pennsylvania, Patrick McLane was declared the winner in the 10th district; a congressional committee determined in 1921 that "wholesale fraud" had cheated John R. Farr out of the election, and McLane was unseated.
1920s In the 1926 United States Senate election in Pennsylvania, there was tampering of ballots that affected the vote count in favor of William Scott Vare against his opponent William B. Wilson. While the fraudulent ballots were not greater than the margin of victory, Vare was ultimately not seated by Congress due to campaign finance improprieties.
1930s In the 1930s, U.S. senator and governor Huey Long ran a political machine throughout Louisiana with significant voter fraud. In the 1930 United States Senate election in Louisiana, which Long won, indications of electoral fraud were ubiquitous. According to Long biographer Richard White, "the official record indicated that voters marched to the polls in alphabetical order". In the 1932 United States Senate election in Louisiana, Long's lieutenants allegedly promised the families of inmates that their loved ones would be freed if they voted for Long's endorsed candidate. In 1933, Orleans Parish District Attorney Eugene Stanley indicted 513 New Orleans election officials for fraud. Three were convicted of falsifying election returns, but after Long as governor pushed the legislature to pass a bill stating prosecutors would have to prove someone committed electoral fraud "willingly", charges against the other 510 were dropped. In the 1934 United States Senate election in Missouri, there was electoral fraud in the Democratic primary connected to Kansas City machine boss Tom Pendergast. There was also fraud related to Pendergast in 1936, after which the FBI investigated. By mid-1938, 242 people had either pled guilty or been convicted at trial for their involvement. In a 1935 St. Louis, Missouri referendum on funding the future Gateway Arch National Park, there was evidence that fraud had led to the referendum passing. The St. Louis Post-Dispatch published an exposé that included affidavits from people who said they hadn't voted.
1940s In the 1941 United States Senate special election in Texas, according to a book by Lyndon B. Johnson biographer Robert A. Caro, Johnson lost due to the manipulation of election results from alcohol industry lobbyists, who sought to elect his rival, governor Pappy O'Daniel. O'Daniel was put over the top thanks to late vote returns.