May 1st
- 1840: The First Adhesive Postage Stamp Is Released
- 1852: Calamity Jane Is Born
- 1931: The Empire State Building Is Dedicated
- 1947: Evelyn McHale Dies By Suicide
- 2001: Chandra Levy Disappears
- 2003: Aron Ralston Amputates His Own Arm
May 2nd
- 1536: Anne Boleyn Is Jailed For Adultery
- 1729: Catherine The Great Is Born In Prussia
- 1878: The Washburn Mill Explosion Takes Place
- 1933: The First Known Sighting Of The Loch Ness Monster Is Reported
- 1957: The Attempted Assassination Of Frank Costello
- 1972: J. Edgar Hoover Dies
- 2011: Osama Bin Laden Is Killed
May 3rd
- 1469: Niccolò Machiavelli Is Born
- 1494: Columbus Encounters The Island Of Jamaica
- 1893: The Panic Of 1893 Begins
- 1979: Margaret Thatcher Becomes The First Female Prime Minister Of Great Britain
- 1980: Cari Lightner Is Killed By A Drunk Driver
- 2007: Madeleine McCann Goes Missing
May 4th
- 1886: The Haymarket Riot Breaks Out
- 1905: Construction Begins On The Panama Canal
- 1929: Audrey Hepburn Is Born
- 1945: The 'Eagle's Nest' Is Captured By U.S. Troops
- 1961: The Freedom Riders Begin Their Historic Journeys
- 1970: The Kent State Massacre Leaves Four Dead
- 2004: David Reimer Commits Suicide
May 5th
- 1818: Karl Marx Is Born
- 1821: Napoleon Bonaparte Dies
- 1862: Mexico Wins The Battle Of Puebla
- 1864: Nellie Bly Is Born
- 1961: Alan Shepard Becomes The First American In Space
- 1981: Bobby Sands Dies
May 6th
- 1856: Sigmund Freud Is Born
- 1937: The Hindenburg Bursts Into Flames
- 1994: English Channel Tunnel Opens
- 1996: Former CIA Director William Colby Drowns
- 1998: Steve Jobs Introduces The iMac Computer
- 2013: Ariel Castro's Victims Are Rescued
May 7th
- 1824: Beethoven Debuts Symphony No. 9
- 1896: H. H. Holmes Is Hanged
- 1915: The Sinking Of The Lusitania
- 1919: Eva Perón, First Spouse Of Argentina, Is Born
- 1960: Leonid Brezhnev Becomes General Secretary Of The U.S.S.R.
May 8th
- 1753: Miguel Hidalgo Is Born
- 1886: The First Coca-Cola Is Sold
- 1902: Mount Pelée Erupts
- 1945: V-E Day
- 1950: Tollund Man Is Found
- 1991: Paula Jones Claims That Bill Clinton Sexually Harassed Her
- 2018: Rily Gaul Is Sentenced To Life In Prison For Murder Of Emma Walker
May 9th
- 1502: Columbus Launches His Final Voyage
- 1800: John Brown Is Born
- 1887: Buffalo Bill's Wild West Show Opens In London
- 1947: Willie Francis Faces The Electric Chair For The Second Time
- 1960: The First Birth Control Pill Is Approved
May 10th
- 1676: Bacon's Rebellion Begins
- 1818: Paul Revere Dies
- 1838: John Wilkes Booth Is Born
- 1869: The Transcontinental Railroad Is Completed
- 1924: J. Edgar Hoover Takes Charge Of The FBI
- 1940: Winston Churchill Becomes Prime Minister Of Britain
- 1977: Actress Joan Crawford Dies
- 1994: Nelson Mandela Inaugurated As President Of South Africa
- 1994: The 'Killer Clown' John Wayne Gacy Is Put To Death
May 11th
- 330 C.E: Constantinople Is Consecrated
- 1811: Conjoined Twins Chang And Eng Bunker Are Born
- 1894: The Pullman Strike Begins In Chicago
- 1969: The Battle Of Hamburger Hill Begins
- 1981: Bob Marley Dies
- 1996: Beck Weathers "Dies" on Mount Everest
May 12th
- 1593: Playwright Thomas Kyd Is Arrested For Libel
- 1820: Florence Nightingale Is Born
- 1889: Otto Frank Is Born
- 1932: The Lindbergh Baby Is Found Dead
- 1935: The First Alcoholics Anonymous Meeting Takes Place
- 1949: The Soviet Union Lifts The Blockade Of Berlin
May 13th
- 1568: Mary, Queen of Scots Is Defeated By Scottish Protestants
- 1607: Settlers Arrive In Virginia
- 1846: The U.S. Declares War On Mexico
- 1862: Robert Smalls Escapes Slavery By Stealing A Ship
- 1985: The MOVE Bombing In Philadelphia
May 14th
- 1607: The Colony Of Jamestown Is Established
- 1796: Edward Jenner Tests History's First Smallpox Vaccine
- 1804: Lewis And Clark Begin Their Expedition Of The American West
- 1939: Lina Medina Becomes The Youngest Person To Ever Give Birth
- 1948: The State of Israel Is Founded
- 1998: Frank Sinatra Dies
- 2008: Brandon Swanson Vanishes
May 15th
- 1756: The Seven Years' War Begins
- 1856: L. Frank Baum Is Born
- 1886: Emily Dickinson Dies
- 1940: The First McDonald's Opens For Business
- 1943: Bomb-Equipped Bats Accidentally Destroy A U.S. Air Force Base
- 1972: Arthur Bremer Shoots Governor George Wallace
May 16th
- 1717: Voltaire Is Imprisoned
- 1770: Marie Antoinette Marries Louis XVI
- 1929: The First Academy Awards Are Held
- 1966: Mao Zedong Releases The May 16 Notification
- 2006: Rey Rivera Disappears
May 17th
- 1510: Sandro Botticelli Dies
- 1792: The New York Stock Exchange Is Created
- 1875: The First Kentucky Derby Takes Place
- 1954: Brown V. Board Of Education Deems Segregation Unconstitutional
- 2001: Alissa Turney Disappears
May 18th
- 1804: Napoleon Proclaims Himself Emperor
- 1918: Pope John Paul II Is Born
- 1927: The Bath School Massacre Leaves 45 Dead
- 1980: Mount St. Helens Erupts
- 2017: Grunge Legend Chris Cornell dies
May 19th
- 1536: Anne Boleyn Is Beheaded
- 1884: Ringling Brothers Circus Opens
- 1897: Oscar Wilde Is Released From Prison
- 1925: Pol Pot Is Born
- 1935: Lawrence Of Arabia Dies
- 1983: Diane Downs Attempts to Murder Her Three Children
May 20th
- 1498: Vasco da Gama Arrives In India
- 1506: Christopher Columbus Dies
- 1743: Toussaint L'Ouverture Is Born
- 1862: Homestead Act Is Signed Into Law
- 1873: Levi Strauss Patents Blue Jeans
- 1902: Cuba Gains Its Independence From The United States
- 1916: Ernest Shackleton Reaches The Stromness Whaling Station
- 1959: Israel Kamakawiwo'ole Is Born
May 21st
- 1542: Hernando de Soto Dies
- 1796: Ona Judge Escapes From George Washington
- 1799: Mary Anning Is Born
- 1881: The American Red Cross Is Founded
- 1924: Nathan Leopold And Richard Loeb Murder Bobby Franks To Create The "Perfect Crime"
- 1927: Charles Lindbergh Completes His Transatlantic Flight
- 1960: Jeffrey Dahmer Is Born
May 22nd
- 1455: The War Of The Roses Begins
- 1843: The First Major Wagon Train Goes West On The Oregon Trail
- 1856: Congressman Preston Brooks Beats Senator Charles Sumner With A Cane
- 1859: Sir Arthur Conan Doyle Is Born
- 1939: The Pact Of Steel Is Signed
- 1960: The World's Most Powerful Earthquake Hits Chile
- 2002: Chandra Levy's Remains Are Found
May 23rd
- 1701: Captain Kidd Is Executed
- 1901: Blanche Monnier Is Discovered In Her Family's Attic
- 1918: The Axeman Of New Orleans Strikes For The First Time
- 1934: Bonnie And Clyde Are Killed
- 1960: A Tsunami Hits Hawaii
- 1981: Peter Sutcliffe Is Convicted Of The "Yorkshire Ripper" Murders
- 1998: Francys Arsentiev, The First Woman To Reach Mount Everest's Summit Without An Oxygen Mask, Dies
- 2013: Gabriel Fernandez Is Murdered By His Parents
May 24th
- 1543: Nicolaus Copernicus Dies
- 1819: Queen Victoria Is Born
- 1883: The Brooklyn Bridge Opens
- 1943: Josef Mengele Arrives At Auschwitz
May 25th
- 1660: The English Restoration Begins
- 1787: The U.S. Constitutional Convention Gets Underway
- 1895: Oscar Wilde Is Sent To Prison For Sodomy
- 1946: Marcel Petiot Is Executed
- 1979: Etan Patz Is Kidnapped
- 1979: The Crash Of American Airlines Flight 191
- 1986: 'Hands Across America' Takes Place
May 26th
- 1637: The Pequot Massacres Begin
- 1896: Nicholas II Is Crowned Czar
- 1897: Dracula Is Published
- 1907: John Wayne Is Born
- 1940: The Evacuation Of Dunkirk Begins
- 1957: Mary Bell Is Born
- 1967: Bassist Kristen Pfaff Is Born
- 2014: Broaddus Family Receives Their First Letter From The Watcher
May 27th
- 1703: St. Petersburg Is Founded
- 1837: "Wild Bill" Hickok Is Born
- 1937: The Golden Gate Bridge Opens
- 1941: The German Battleship Bismarck Sinks
- 1962: The Centralia Mine Fire Begins
- 1995: Christopher Reeve Becomes Paralyzed
May 28th
- 1830: The Indian Removal Act Is Signed Into Law
- 1937: Volkswagen Is Founded
- 1961: Amnesty International Is Founded
- 1964: The Palestine Liberation Organization Is Founded
- 1998: Phil Hartman Is Murdered
May 29th
- 1453: Constantinople Falls To The Ottoman Empire
- 1917: John F. Kennedy Is Born
- 1953: Edmund Hillary And Tenzing Norgay Summit Mt. Everest
- 1979: Charles Harrelson Murders Judge John Wood Jr.
- 1997: Jeff Buckley Dies
May 30th
- 1431: Joan Of Arc Is Burned At The Stake
- 1539: Christopher Marlowe Is Killed
- 1913: The First Balkan War Ends
- 2005: Natalee Holloway Disappears
- 2014: The Infamous "Slender Man Stabbing"
May 31st
- 1819: Walt Whitman Is Born
- 1859: Big Ben Rings For The First Time
- 1889: The Johnstown Flood Kills 2,000 People
- 1911: The RMS Titanic Leaves Its Dry Dock
- 1921: The Tulsa Race Massacre Begins
- 1962: Adolf Eichmann Is Hanged
- 1996: Benjamin Netanyahu Is Elected Prime Minister Of Israel
- 2005: The Identity Of 'Deep Throat' Is Revealed
- 2009: Millvina Dean, The Last Survivor Of The Titanic, Dies
- 2014: The "Slender Man" Stabbing Nearly Kills Payton Leutner
