1775: The American Revolution begins as British and American soldiers exchange fire in the Massachusetts towns of Lexington and Concord
1824: Lord Byron dies of a fever contracted in Greece, where he is participating in the rebellion against the Ottoman Empire; his heart is in Greece, his body in England
1943: Albert Hofmann deliberately ingests 250 micrograms of LSD (after having accidentally absorbed some three days earlier)
1951: Shigeki Tanaka, a survivor of the atomic blast at Hiroshima, wins the Boston Marathon in 2:27:45
1971: In Washington DC, “Operation Dewey Canyon III” (Vietnam Veterans Against the War) begins in earnest with a march to Arlington National Cemetery
1993: The siege on the Branch Davidian compound in Waco, Texas ends in a great big fire
1995: Timothy McVeigh bombs the Alfred P. Murrah Federal Building in Oklahoma City