18 April History
- 310 - St. Eusebius begins his reign as Catholic Pope.
- 1521 - Martin Luther confronts the emperor Charles V, refusing to retract the views which led to his excommunication.
- 1676 - Sudbury, Massachusetts is attacked by Indians.
- 1775 - American revolutionaries Paul Revere and William Dawes ride though the towns of Massachusetts warning that "the British are coming."
- 1791 - National Guardsmen prevent Louis XVI and his family from leaving Paris.
- 1818 - A regiment of Indians and blacks is defeated at the Battle of Suwanna, in Florida, ending the first Seminole War.
- 1834 - William Lamb becomes prime minister of England.
- 1838 - The Wilkes' expedition to the South Pole sets sail.
- 1847 - U.S. forces defeat Mexicans at Cerro Gordo in one of the bloodiest battle of the war.
- 1853 - The first train in Asia begins running from Bombay to Tanna.
- 1861 - Colonel Robert E. Lee turns down an offer to command the Union armies.
- 1885 - The Sino-Japanese war ends.
- 1906 - A massive earthquake hits San Francisco, measuring 8.25 on the Richter scale.
- 1923 - Yankee Stadium opens with Babe Ruth hitting a three-run homer as the Yankees beat the Red Sox 4-1.
- 1937 - Leon Trotsky calls for the overthrow of Soviet leader Josef Stalin.
- 1942 - James H. Doolittle bombs Tokyo and other Japanese cities.
- 1943 - Traveling in a bomber, Japanese Admiral Isoroku Yamamoto, the mastermind of the attack on Pearl Harbor, is shot down by American P-38 fighters.
- 1946 - The League of Nations dissolves.
- 1949 - The Republic of Ireland withdraws from British Commonwealth.
- 1950 - The first transatlantic jet passenger trip is completed.
- 1954 - Colonel Nasser seizes power in Egypt.
- 1978 - The U.S. Senate approves the transfer of the Panama Canal to Panama.
- 1980 - Zimbabwe's (Rhodesia) formal independence from Britain is proclaimed.
- 1983 - A suicide bomber kills U.S. Marines at the U.S. Embassy in Lebanon.
18 April Birthdays
- 1480 - Lucretia Borgia, daughter of Pope Alexander VI and a patron of the arts.
- 1817 - George Henry Lewes, philosophical writer.
- 1857 - Clarence S. Darrow, lawyer.
- 1864 - Richard Harding Davis, journalist.
- 1918 - Clifton Keith Hillegass, founder of the study guides known as Cliff's Notes.
- 1940 - Ed Garvey, labor leader.