In his final race, Michael Phelps helped the United States men's swimming team to a gold medal in the 4x100 medley relay. Ryan Murphy, Cody Miller and Nathan Adrian gave the U.S. the gold.
Phelps took to his facebook page before the race to announce the 4x100 would be his last professional race.
Kathleen Baker, Lilly King, Dana Vollmer and Simone Manuel of the United States women's team also picked up another gold medal in the 4x100m medley relay final.
The win was 1000th gold medal for the United States in their Olympic history.
As a whole, the men's and women's team collected 33 medals in swimming for the United States.