The Apollo program was the United States' effort to land humans on the Moon and return them safely to Earth, run by NASA from 1961 through 1972. It grew out of a 1961 challenge from President John F. Kennedy and ultimately involved more than 400,000 engineers, scientists, and technicians.
Six missions made it to the lunar surface: Apollo 11 (Sea of Tranquility, July 1969), Apollo 12 (Ocean of Storms), Apollo 14 (Fra Mauro), Apollo 15 (Hadley–Apennine), Apollo 16 (Descartes Highlands), and Apollo 17 (Taurus–Littrow, December 1972). Apollo 13 famously did not land, but its crew returned home after an oxygen tank failure on the way out.
Together the crews spent about 80 hours walking and driving on the Moon, deployed long-running scientific instruments, and brought back roughly 382 kilograms of lunar rock and soil. Those samples are still being studied today.
This site collects notes and references about the landings — the sites, the crews, the hardware, and the science that came out of them.