1889

The Oklahoma Land Rush began at noon as thousands of homesteaders staked claims to nearly 1.9 million acres of land that was formerly part of Indian Territory. By the end of the day, the cities of Oklahoma City and Guthrie were established with as many as 10,000 settlers each.

1915

German forces unleashed its first full-scale use of chlorine gas against Allied troops at the start of the Second Battle of Ypres in Belgium during World War I. Thousands of Allied soldiers are believed to have died from the poison gas attacks.

1970

An estimated 20 million Americans participated in gatherings for the first Earth Day, a series of events proposed by Sen. Gaylord Nelson of Wisconsin to promote environmental protections.

2005

Zacarias Moussaoui pleaded guilty in a federal courtroom outside Washington, D.C., to conspiring with the Sept. 11 hijackers to kill Americans. (Moussaoui was sentenced to life in prison in May 2006.)

Birthdays

Actor Jack Nicholson is 88. Singer Mel Carter is 86. Author Janet Evanovich is 82. Filmmaker John Waters is 79. Singer Peter Frampton is 75. Actor-comedian Ryan Stiles is 66. Actor Jeffrey Dean Morgan is 59. Actor Sheryl Lee is 58. Actor-talk show host Sherri Shepherd is 58. Actor Eric Mabius is 54. Entrepreneur Sam Altman is 40. Actor Amber Heard is 39.