| 1492 | | King Ferdinand and Queen Isabella sign a decree expelling all Jews from Spain. |
| 1840 | | "Beau" Brummell, the English dandy and former favorite of the prince regent, dies in a French lunatic asylum for paupers. |
| 1858 | | Hyman L. Lipman of Philadelphia patents the pencil with an eraser attached on one end. |
| 1867 | | Russian Baron Stoeckl and U.S. Secretary of State Seward completed the draft of a treaty ceding Alaska to the United States. The treaty is signed the following day. |
| 1870 | | The 15th amendment, guaranteeing the right to vote regardless of race, passes. |
| 1885 | | Texas is the last Confederate state readmitted to the Union. |
| 1885 | | In Afghanistan, Russian troops inflict a crushing defeat on Afghan forces Ak Teppe despite orders not to fight. |
| 1909 | | The Queensboro Bridge in New York opens. It is the first double decker bridge and links Manhattan and Queens. |
| 1916 | | Mexican bandit Pancho Villa kills 172 at the Guerrero garrison in Mexico. |
| 1936 | | Britain announces a naval construction program of 38 warships. This is the largest construction program in 15 years. |
| 1941 | | The German Afrika Korps under General Erwin Rommel begins its first offensive against British forces in Libya. |
| 1943 | | Rodgers and Hammerstein's first collaboration, Oklahoma, opens on Broadway. |
| 1944 | | The U.S. fleet attacks Palau, near the Philippines. |
| 1945 | | The Red Army advances into Austria. |
| 1946 | | The Allies seize 1,000 Nazis attempting to revive the Nazi party in Frankfurt. |
| 1950 | | President Harry S Truman denounces Senator Joe McCarthy as a saboteur of U.S. foreign policy. |
| 1957 | | Tunisia and Morocco sign a friendship treaty in Rabat. |
| 1972 | | Hanoi launches its heaviest attack in four years, crossing the DMZ. |
| 1975 | | As the North Vietnamese forces move toward Saigon, desperate South Vietnamese soldiers mob rescue jets. |
| 1981 | | President Ronald Reagan is shot and wounded in Washington, D.C. by John W. Hinkley Jr. |
| 1987 | | Vincent Van Gogh's Sunflowers is bought for $39.85 million. | |
Born on March 30 |
| 1719 | | Sir John Hawkins, author of the first history of music. |
| 1820 | | Anna Sewell, English novelist (Black Beauty). |
| 1853 | | Vincent Van Gogh, Dutch impressionist artist. |
| 1880 | | Sean O'Casey, Irish playwright. |
| 1883 | | Jo Davidson, American sculptor. |
