Opera Opens (Jan. 7): Contralto Marian Anderson becomes the first black person to sing at the New York Metropolitan Opera House.

Conference on Camera (Jan. 19): President Dwight D. Eisenhower allows filming of a presidential news conference for the first time. TV and motion picture newsreel photographers cover the event.

Hizzoner (April 5): Richard J. Daley, formerly Cook County Democratic Party chairman, is elected mayor of Chicago and begins his 21-year career as mayor of the nation's second-largest city.

Delightful Doh: Kenner toy company comes out with Play-Doh, a non-toxic substance that's easier than clay for little hands to shape.

Polio Breakthrough (April 12): Jonas Salk, a research scientist who specializes in viruses, becomes a household name after he announces that field trial results on a vaccine for polio have proven the treatment safe and effective. Salk refuses to patent the vaccine. He says he has no desire to profit from the discovery, only to help people.

Out of Control (June 11): Eighty people die and nearly 100 are injured as the worst accident in the history of auto racing occurs at Le Mans, France. Three cars are involved in the accident, and one of the cars slams into a grandstand.

Soviet Threat (June 24): Soviet MiGs shoot down a U.S. Navy patrol plane over the Bering Strait.

Magic Kingdom (July 17): Disneyland opens in Anaheim, Calif. Part amusement park, part multimedia wonder, the 160-acre theme park is the first of its kind. Because potential investors had been a bit cool to Walt Disney's dream, the entertainment giant had to come up with most of the $17 million to build the Magic Kingdom. As with most things Disney touched, Disneyland is an instant success.

Peron Powerless (Sept. 19): The 10-year government of Argentine President Juan Peron ends with his resignation after a three-day revolt by military forces. Peron is exiled to Paraguay on Sept. 24.

Dramatic Death (Sept. 30): Actor James Dean, 24, dies instantly when his Porsche Spyder skids off a road near Paso Robles, Calif., and smashes into a telephone pole. Four days after his death, Warner Bros. releases, on schedule, "Rebel Without a Cause," director Nicholas Ray's drama of juvenile delinquency.

United Labor (Dec. 5): The American Federation of Labor and the Congress of Industrial Organizations merge, with George Meany as AFL-CIO leader.