Today:
1215 – King John of England sealed the Magna Carta at Runnymede.
1381 – Wat Tyler, leader of the English Peasants’ Revolt, was killed during a meeting with King Richard II.
1520 – Pope Leo X issued the papal bull Exsurge Domine, threatening Martin Luther with excommunication.
1752 – Benjamin Franklin reportedly performed his famous kite experiment involving lightning and electricity.
1775 – George Washington was appointed commander in chief of the Continental Army.
1846 – The Oregon Treaty was signed, establishing the 49th parallel as much of the U.S.–Canada border in the Pacific Northwest.
1849 – James K. Polk, the 11th president of the United States, died in Nashville, Tennessee.
1864 – Arlington National Cemetery was established on land once belonging to Confederate General Robert E. Lee’s family.
1904 – The General Slocum steamboat disaster occurred in New York City, killing more than 1,000 people.
1991 – Mount Pinatubo in the Philippines erupted in one of the largest volcanic eruptions of the 20th century.