There is a library association for nearly every possible type of library, nationally and internationally. Many of these have a closed institutional membership decree, but many more are open to individual membership. Often these associations feature a national coalition, as well as regional and state divisions.
Associations are based on types of:
Environment: academic, public, special, school;
Further Specialization: church, law, medical, theater
Function: advocacy, political, cataloging, reference
Background of Individual: ethnicity, orientation
Service Population: rural, city, youth
State and National Boundaries