Which rocket carried the first American astronaut into space in 1961?

A Redstone rocket carried Alan Shepard on the first American crewed spaceflight in 1961.

The Mercury-Redstone 3 mission, also called Freedom 7, launched from Cape Canaveral on 5 May 1961. Shepard made a suborbital flight lasting about 15 minutes, reaching an altitude of roughly 187 kilometres before splashing down in the Atlantic Ocean. He became the first American in space, although he did not orbit Earth.

The Redstone was a liquid-fuelled rocket derived from the United States Army’s Redstone ballistic missile. For Mercury, engineers modified it with systems for crew safety and precise flight control. The vehicle was smaller and less powerful than the Atlas rocket used for later Mercury orbital missions.

John Glenn became the first American to orbit Earth on Mercury-Atlas 6 in February 1962. Shepard later travelled to the Moon as commander of Apollo 14. Thus, the Redstone is linked specifically with the first American in space, while Atlas is linked with the first American orbital flight.