Billiard Congress of America
The BCA is the sanctioning body for most (All?) professional billiard events.
Formed in 1948, the BCA was formed to organize the players and promote the "sport" of billiards, while also defining a standard set of rules and promoting local, regional, and national tournaments allowing a national champion to be determined.
The BCA also works to get local pool halls and equipment manufacturers involved in the promotion of tournament events in hopes of cleaning up the rough reputation billiards has acquired and gain more players and a wider audience.
http://www.bca-pool.com