On Oct. 20, 1803, the U.S. Senate ratified the Louisiana Purchase.

In 1947, the House Un-American Activities Committee opened hearings into alleged Communist influence in the U.S. motion picture industry.

In 1973, in the so-called “Saturday Night Massacre,” special Watergate prosecutor Archibald Cox was dismissed, and Attorney General Elliot L. Richardson and Deputy Attorney General William B. Ruckelshaus resigned.

In 1977, three members of the rock group Lynyrd Skynyrd were killed along with three others in the crash of a chartered plane near McComb, Mississippi.

In 1999, the government laid out new rules to protect children’s privacy on the Internet.

In 2001, officials announced that anthrax had been discovered in a House postal facility on Capitol Hill.