Astronaut Alan Shepard was the first American in space. According to History.com, on May 5, 1961:

“From Cape Canaveral, Florida, Navy Commander Alan Bartlett Shepard Jr. is launched into space aboard the Freedom 7 space capsule, becoming the first American astronaut to travel into space. The suborbital flight, which lasted 15 minutes and reached a height of 116 miles into the atmosphere, was a major triumph for the National Aeronautics and Space Administration (NASA).”

The first man in space was Soviet cosmonaut Yuri Gagarin, who less than a month before Shephard’s flight became the first man to orbit the earth in an April 12, 1961 flight lasting 108 minutes.