Events
- 1807 – A grand jury indicts former Vice President of the United States Aaron Burr on a charge of treason.
- 1819 – The SS Savannah leaves port at Savannah, Georgia, United States, on a voyage to become the first steamship to cross the Atlantic Ocean. The ship arrived at Liverpool, England on June 20.
- 1842 – Farmers Lester Howe and Henry Wetsel discover Howe Caverns, when they stumble upon a large gaping hole in the ground.
- 1843 – Thousands of people and their cattle headed west via wagon train from Independence, Missouri to what would later become the Oregon Territory. It was part of the Great Migration. They followed what is now known as the Oregon Trail.
- 1856 – Congressman Preston Brooks of South Carolina beats Senator Charles Sumner with a cane in the hall of the United States Senate for a speech Sumner had made attacking Southerners who sympathized with the pro–slavery violence in Kansas ("Bleeding Kansas").
- 1872 – Reconstruction: U.S. President Ulysses S. Grant signs the Amnesty Act of 1872 into law restoring full civil rights to all but about 500 Confederate sympathizers.
- 1906 – Wright brothers are granted U.S. patent number 821,393 for their "Flying–Machine".
- 1915 – Lassen Peak erupts with a powerful force, and is the only mountain to erupt other than Mount St. Helens in the continental US during the 20th century.
- 1942 – The Steel Workers Organizing Committee disbands, and a new trade union, the United Steelworkers, is formed.
- 1942 – World War II: Ted Williams of the Boston Red Sox enlists in the United States Marine Corps as a flight instructor.
- 1947 – Cold War: In an effort to fight the spread of Communism, U.S. President Harry S. Truman signs an act into law that will later be called the Truman Doctrine. The act grants $400 million in military and economic aid to Turkey and Greece.
- 1962 – Continental Airlines Flight 11 crashes after bombs explode.
- 1964 – U.S. President Lyndon B. Johnson announces the goals of his Great Society social reforms to bring an "end to poverty and racial injustice" in America.
- 1968 – The nuclear–powered submarine the USS Scorpion sinks with 99 men aboard 400 miles (640 km) southwest of the Azores.
- 1969 – Apollo 10's lunar module flies within 8.4 nmi (15.6 km) of the moon's surface.
- 1990 – The Windows 3.0 operating system is released by Microsoft.
- 1992 – After 30 years, 66–year–old Johnny Carson hosts The Tonight Show for the last time.
- 1997 – Kelly Flinn, US Air Force's first female bomber pilot certified for combat, accepts a general discharge in order to avoid a court martial.
- 1998 – Lewinsky scandal: A federal judge rules that United States Secret Service agents can be compelled to testify before a grand jury concerning the scandal, involving President Bill Clinton.
- 2002 – In Washington, DC, the remains of the missing Chandra Levy are found in Rock Creek Park.
- 2002 – American civil rights movement: A jury in Birmingham, Alabama, convicts former Ku Klux Klan member Bobby Frank Cherry of the 1963 murders of four girls in the bombing of the 16th Street Baptist Church.
- 2003 – In Fort Worth, Texas, Annika Sörenstam becomes the first woman to play the PGA Tour in 58 years.
- 2004 – The U.S. town of Hallam, Nebraska, is wiped out by a powerful F4 tornado that broke a width record at an astounding 2.5 miles (4.0 km) wide. It also killed one local resident.