After a long winter, the Lewis and Clark expedition departs its camp among the Mandan tribe and resumes its journey West.

On April 7, 1949, the Rodgers and Hammerstein musical South Pacific opens at the Majestic Theatre on Broadway in New York City. The romantic musical about World War II, which touches on controversial racial themes, goes on to run for almost five years, becoming one of the most popular musicals of the 1950s. The show won 10 Tony Awards, and six decades later, its Lincoln Center revival would earn another seven, making it the most Tony Award-winning show in New York theater history.

By a vote of 57 to 1, Dag Hammarskjöld is elected secretary-general of the United Nations.

President Dwight D. Eisenhower coins one of the most famous Cold War phrases when he suggests the fall of French Indochina to the communists could create a “domino” effect in Southeast Asia. The so-called “domino theory” dominated U.S. thinking about Vietnam for the next decade.

On April 7, 1963, a new Yugoslav constitution proclaims Tito the president for life of the newly named Socialist Federal Republic of Yugoslavia.

On April 7, 1979, nearly a year after his brother Bob pitched a no-hitter, Houston Astros pitcher Ken Forsch tosses his first career no-hitter. Ken and Bob become the first—and only—brothers to pitch official no-hitters in Major League Baseball history.

On April 7, 1994, violence fuels the launch of what would become the worst episode of genocide since World War II: the massacre of an estimated 500,000 to 1 million innocent civilian Tutsis and moderate Hutus. Following the first wave of massacres, Rwandan forces manage to discourage international intervention with the murder of 10 Belgian peacekeeping officers. The Tutsis, a minority group that made up about 10 percent of Rwanda’s population, received no assistance from the international community, although the United Nations later conceded that a mere 5,000 soldiers deployed at the outset would have stopped the wholesale slaughter.