February 23

February 23 in history:

• 1997: Dr. Ian Wilmut and his colleagues at the Roslin Institute, Edinburgh, Scotland, announced that they had succeeded in cloning a lamb called Dolly from the mammary gland of an adult sheep.

• 1991: President George Bush announced that the ground assault to expel Iraqi forces from Kuwait during the Persian Gulf War had begun; in the Middle East, it was already February 24.

• 1987: A supernova was detected in the relatively nearby Large Magellanic Cloud by an astronomer at Chile's Las Campanas Observatory; because it is so close (and actually visible to the naked eye), it became the object of intense study.

• 1954: The first mass inoculation of children against poliomyelitis took place, in Pittsburgh, Pa., testing the vaccine developed by Jonas Salk.

• 1848: John Quincy Adams, the former president of the United States, died at the U.S. Capitol, where he collapsed at his desk from a stroke; he had served in the House of Representatives since 1831.

• 1836: During the Texas Revolution, Mexican general Antonio López de Santa Anna began his siege of the Alamo.