History
The U. S. Women's Open Championship was established by US Sailing in 1974 for national competition in single-handed and double-handed boats. The Allegra Knapp Mertz Trophy was given for the single-handed championship, the Adams Memorial Trophy for the double-handed championship. From 1981 through 1992, there was also a boardsailing championship.
In 2001, the competition was changed from fleet racing to match racing. However, that year's race was cancelled, so the new format didn't go into effect until 2002. The Mertz Trophy is awarded to the winner and the runner-up receives the Adams Trophy. Racing is conducted in a different class each year and entry is by invitation.