The first spacecraft launched by the United States was part of Project Mercury, which began in 1958 and flew six manned space flights between 1961 and 1963. This cone-shaped capsule held one man and was equipped with parachutes to slow its descent and an escape tower to assist astronauts in an emergency. Of those six manned Mercury missions, four were orbital (where the spacecraft is in space for an orbit around the planet) and two were suborbital flights (which reaches space but doesn’t orbit).
Following Project Mercury, the Gemini Program flew twelve missions in the mid-1960s, ten of which were manned. These capsules were bigger, holding two astronauts, and were critical to the success of the later Apollo Program and moon landing. Unlike the Mercury spacecraft, the Gemini vehicles did not have an escape tower and instead relied on ejection seats to launch the crew away from the spacecraft at low altitudes when it was necessary to disembark.
The Apollo spacecraft was the next big innovation in the space program. It contained three separate sections, or modules (command, service, and lunar), which made it possible for the US to successfully land on the Moon. Once in lunar orbit, the lunar module shuttled astronauts to the surface of the Moon and returned them to the relative safety of the command and service modules in orbit. Six of the Apollo missions landed twelve men on the Moon and safely returned them to Earth.