| 1416 | | Jerome of Prague is burned as a heretic by the Church. |
| 1431 | | Joan of Arc is burned at the stake by the English. |
| 1527 | | The University of Marburg is founded in Germany. |
| 1539 | | Hernando de Soto lands in Florida with 600 soldiers in search of gold. |
| 1783 | | The first American daily newspaper, The Pennsylvania Evening Post, begins publishing in Philadelphia. |
| 1814 | | The First Treaty of Paris is declared, returning France to its 1792 borders. |
| 1848 | | William Young patents the ice cream freezer. |
| 1854 | | The Kansas-Nebraska Act repeals the Missouri Compromise. |
| 1859 | | The Piedmontese army crosses the Sesia River and defeats the Austrians at Palestro. |
| 1862 | | Union General Henry Halleck enters Corinth, Mississippi. |
| 1868 | | Memorial Day begins when two women place flowers on both Confederate and Union graves. |
| 1889 | | The brassiere is invented. |
| 1912 | | U.S. Marines are sent to Nicaragua to protect American interests. |
| 1913 | | The First Balkan War ends. |
| 1921 | | The U.S. Navy transfers the Teapot Dome oil reserves to the Department of the Interior. |
| 1942 | | The Royal Air Force launches the first 1,000 plane raid over Germany. |
| 1971 | | NASA launches Mariner 9, the first satellite to orbit Mars. |
Born on May 30 |
| 1672 | | Peter I (the Great) czar of Russia. |
| 1867 | | Arthur Vining Davis, American industrialist. |
| 1903 | | Countee Cullen, American poet. |
| 1908 | | Hannes Alfvén, Swedish, Nobel Prize-winning astrophysicist. |
| 1908 | | Mel Blanc, American entertainer, vocal artist. |
| 1909 | | Benny Goodman, musician, big band leader. |
| 1916 | | Joseph W. Kennedy, scientist, co-discoverer of plutonium. |
