4 links
American Amateur Baseball Congress
aabc.us
Coordinates play among US leagues in seven age brackets, from sub-teens through adults. Includes rules, tournament dates, and list of regions and age divisions.
National Adult Baseball Association
dugout.org
NABA amateur baseball organization information, including tournament results, events and how to join.
Vintage Base Ball Association
vbba.org
Listing of rules, tournaments, members and contact information.