1529 – At the Second Diet of Speyer, a group of rulers and independent cities protests the reinstatement of the Edict of Worms, beginning the Protestant movement.
1775 – The Battle of Lexington and Concord begins the American Revolutionary War.
1861 – Baltimore riot of 1861, a pro-Secession mob attacks United States Army troops marching through the city.
1933 – President Franklin D. Roosevelt announces the abandonment of the gold standard.
1943 – The Warsaw Ghetto Uprising begins.
1961 – End of the Bay of Pigs invasion of Cuba. (Oops)
1993 – Eighty-one people are slaughtered by fire, gas and gunfire by forces of the Federal Government at the end of the siege of the Branch Davidian building outside Waco, Texas.
1995 – The Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma, USA, is bombed, killing 168.
And lots of other interesting stuff. It’s rarely good stuff, though some do still believe the Lexington and Concord thing worked out well in the end.