On this day in 1965, the Gemini VII and VI completed the first-ever rendezvous between two spacecraft in orbit.

From NASA:

On this day in 1965, the Gemini VII and VI completed the first-ever rendezvous between two spacecraft in orbit. It was a transformative capability that was not only necessary for the Apollo moon landing missions, but crucial in building and operating the International Space Station. Learn more about this historic event:http://go.nasa.gov/1RQuZdi