Amateur Softball Association of America
Homepage: http://www.softball.org/
Rules and regulations: http://www.softball.org/about/asa_code.asp

History:

The Amateur Softball Association of America (ASA) is credited for establishing a standard set of rules and providing guidance and stability to the sport of softball in the US. Founded in 1933 as a volunteer driven organization, ASA has become one of the most enduring softball organizations in the country. Thus, in 1978 ASA merited the United States Olympic Committee’s recommendation to become the national governing body. Perhaps one of ASA’s greatest accomplishments is being able to expand membership from a few hundred teams in the early days, to an astounding 250,000 teams today, representing 4 million members.

As the national governing body, ASA ensures fairness and equal opportunity play for its players. It is credited for having established the first ever unified set of playing rules for the sport and organizing competitions nationwide. Now, ASA endorses competitions in every state through its 93 member states and metro associations.