A thread follows one event or historical theme across the archive, wherever and whenever it appears. Pulling a thread opens up a narrowed timeline view filtered to every year that thread touches.
The first crewed spaceflight program of the United States. With the Soviet Union already ahead in the Space Race with the deployment of Sputnik 1 as the world's first artificial satellite, Project Mercury's goal was to successfully perform a crewed orbit of the Earth before the Soviets. However, this record would also go to the Soviets with the flight of Yuri Gagarin in 1961.
