The ships undocked on 19 July. Soyuz 19, with Leonov and Kubasov, landed on 21 July on the Kazakh steppe. Apollo stayed in orbit a few more days and on 24 July splashed down in the Pacific near Hawaii — the last flight of an Apollo spacecraft in history.
Apollo's return nearly ended in tragedy: due to a human error in the procedure, toxic nitrogen tetroxide from the manoeuvring thrusters entered the cabin during descent. The crew quickly donned oxygen masks, but Vance Brand briefly lost consciousness. All three astronauts spent about two weeks in hospital in Hawaii and made a full recovery. Apollo–Soyuz ended the Apollo era; the next American crewed flight came only six years later with the Space Shuttle (STS-1, 1981).
NASA — The Apollo-Soyuz Mission · NASA NSSDCA — Apollo-Soyuz Test Project · Spaceline — ASTP Mission Fact Sheet — full list on Apollo–Soyuz