The Apollo-Soyuz Mission 30 Years On

Thomas P. Stafford, Vance D. Brand, Donald K. Slayton (deceased), Alexey A. Leonov, Valery N. Kubasov
On stage at the Apollo building at the Kennedy Space Centre reliving the experience
The first international partnership in space wasn't the International Space Station. It wasn't even the Shuttle-Mir series of missions. It was the Apollo-Soyuz Test Project, the first international human spaceflight. On July 15, 1975, an Apollo spacecraft launched carrying a crew of three and docked two days later on July 17, with a Soyuz spacecraft and its crew of two.

http://www.nasa.gov/mission_pages/apollo-soyuz/index.html