1792: Kentucky becomes the 15th state of the United States.
1869: The first transcontinental railroad in the United States is completed.
1938: Superman makes his first appearance in Action Comics.
1941: Germany invades the Soviet Union, starting Operation Barbarossa.
1967: The Beatles release the album "Sgt. Pepper's Lonely Hearts Club Band".
1979: The United States Supreme Court rules that the death penalty is not cruel and unusual punishment.
1980: CNN, the first 24-hour cable news channel, goes on the air.
1990: President George H.W. Bush signs the Americans with Disabilities Act into law.
1998: Microsoft releases Windows 98.
2001: The first iPod is released.
2004: Same-sex marriage becomes legal in Massachusetts, marking the first state in the United States to legalize it.
2012: Facebook, Inc. becomes a publicly traded company.