Complex sentence: The average age of the U.S. team was 21 years old, making it the youngest team in U.S. team history to play in the Olympics and would be the youngest team in the Olympic tournament.
Split into simpler sentences: The average age of the U.S. team was 21 years old, making it the youngest team in U.S. team history to play in the Olympics. It would be the youngest team in the Olympic tournament.