Two spacecraft drifted closer to one another far above planet Earth, as they prepared to dock. It was July 17th, 1975, and they were about to make history. For the first time, a United States Apollo and Soviet Union Soyuz spacecraft would dock with one another, an enormously symbolic mission that served as a small step towards international cooperation between the two superpowers.
Source: Gizmodo – The First Time NASA Docked with a Soviet Spacecraft in Orbit