Hamill's first national success came in 1969, when she won the novice ladies' title at the U.S. Championships at the age of 12. Later that spring, Hamill was invited to perform in Madison Square Garden with the exhibition tour (in later years known as Champions on Ice) that followed the 1969 World Figure Skating Championships. She placed second at the junior level at the 1970 Championships, and made her senior debut in 1971. The U.S. Figure Skating Association arranged for her to be coached by Carlo Fassi when she began to compete internationally.