Apollo 7 splashed down on October 22, 1968. The spacecraft had spent almost eleven days in orbit, the first crewed flight of the Apollo program, and it proved the machine that would carry men to the Moon. The mission was a success that had to happen.
The program was in trouble. The first Apollo crew, Grissom, White, and Chaffee, had died in a fire during a ground test in 1967, and the whole project was shaken and delayed. Apollo 7 was the flight that showed the redesigned spacecraft was safe.
The crew was three men. Wally Schirra, Donn Eisele, and Walter Cunningham spent the mission testing the command module, and they also broadcast from orbit, the first live television from an American spacecraft. The transmissions were playful and human, and the public liked them.
The crew was also difficult. The men caught colds in space and argued with mission control over their schedule, and Schirra was blunt about it, and none of the three ever flew again. The grumbling did not matter to the mission's success, which was complete.
Apollo 7 cleared the path to the Moon. Two months later Apollo 8 went around it, and the following year Apollo 11 landed on it, and the machine tested on this flight carried them all. The splashdown in the Atlantic on October 22 was the first step back from the fire toward the lunar surface.