After playing as an alternate at the 1998 World Junior Curling Championships for the 5th-place U.S. team skipped (captained) by Hope Schmitt, Cassandra returned to the Junior Championships in 2002, this time as the skip of the team; she and her United States squad went on to capture the gold medal with a win over Matilda Mattsson of Sweden.

At the 2005 World Championships, she again won a silver medal, this time losing to Anette Norberg's Swedish rink in the final.

Johnson's Olympics experience was a difficult one: she and her United States team lost five of their first six matches en route to a 2–7 record in the round-robin stage of the tournament.

At the trials, the team finished in fourth place, losing the 3–4 page game to Margie Smith.

Potter's biography page at NBC's Winter Olympics website was among the most-viewed of any U.S. athlete,[2] and she received countless marriage proposals from men all over the world at the U.S. Women's Curling Team's official blog,[3] which crashed early in the Games after receiving 12.9 million hits in one day.