The mid-seventies was a time of transition for NASA. We had completed the Apollo lunar missions and Skylab, a predecessor to a real space station. We knew that to create a working space station, we would need the cooperation and services from other nations, especially the Soviet Union.
The final flight of the Apollo program was the first spaceflight in which spacecraft from different nations docked in space. In July 1975, a U.S. Apollo spacecraft carrying a crew of three docked with a Russian Soyuz spacecraft with its crew of two. This was to set the stage for future partnerships required to build, support and pay for the now orbiting International Space Station.
This is a replica of the Apollo Command and Service Module (CSM) and the Russian Soyuz 19 spacecraft in the Air and Space Museum in Washington D.C.