"The American Association of Law Libraries was founded in 1906 to promote and enhance the value of law libraries to the legal and public communities, to foster the profession of law librarianship, and to provide leadership in the field of legal information." -- About us AALL

The American Association of School Librarians (AASL), a division of the American Library Association, "is the only national professional membership organization focused on the needs of school librarians and the school library community. We serve the needs of more than 7,000 school librarians in the United States, Canada, and around the world." -- AASL Join.

The Association of College and Research Libraries (ACRL) is a division of the American Library Association. ACRL "is a professional association of academic librarians and other interested individuals. It is dedicated to enhancing the ability of academic library and information professionals to serve the information needs of the higher education community and to improve learning, teaching, and research. ACRL is the largest division of the American Library Association (ALA). ACRL currently has a membership of more than 12,000 members, accounting for nearly 20% of the total ALA membership." -- About ACRL

"The American Library Association (ALA) is the oldest and largest library association in the world, providing association information, news, events, and advocacy resources for members, librarians, and library users. Founded on October 6, 1876 during the Centennial Exposition in Philadelphia, the mission of ALA is to provide leadership for the development, promotion, and improvement of library and information services and the profession of librarianship in order to enhance learning and ensure access to information for all." -- About ALA

Association for Library Collections & Technical Service is a division of the American Library Association. "ALCTS enjoys a rich, 55-year history of service to its members and continues to improve the products and services it offers its members. With strategic and tactical plans firmly in place, ALCTS has a solid foundation from which to expand its influence. Comprised of nearly 4,000 members from across the United States and 42 countries from around the globe, ALCTS is the premier resource for information specialists in collection development, preservation, and technical services. We are the leader in the development of principles, standards, and best practices for creating, collecting, organizing, delivering, and preserving information resources in all forms." -- About ALCTS

Association for Library Service to Children is a division of the American Library Association. "The Association for Library Service to Children (ALSC) is the world's largest organization dedicated to the support and enhancement of library service to children. From creative programming and best practices to continuing education and professional connections—ALSC members are innovators in the field of children's library service. -- About ALSC

"AILA was founded in 1979 in conjunction with the White House Pre-Conference on Indian Library and Information Services on or near Reservations. At the time, there was increasing awareness that library services for Native Americans were inadequate. Individuals as well as the government began to organize to remedy the situation. An affiliate of the American Library Association (ALA), the American Indian Library Association is a membership action group that addresses the library-related needs of American Indians and Alaska Natives. Members are individuals and institutions interested in the development of programs to improve Indian library, cultural, and informational services in school, public, and research libraries on reservations. AILA is also committed to disseminating information about Indian cultures, languages, values, and information needs to the library community. [...]" -- About AILA

"Founded in 1980, the Asian Pacific American Librarians Association (APALA) was incorporated in Illinois in 1981 and formally affiliated with the American Library Association (ALA) in 1982. A predecessor of APALA, the Asian American Librarians Caucus (AALC) was organized in 1975 as a discussion group of the ALA Office for Library Outreach Services reflecting the interest in library services to minority communities and professional support of librarians of minority ancestry during the 1960s and 1970s. APALA, and AALC before it, were organized and founded by librarians of diverse Asian and Pacific ancestries committed to working together toward a common goal: to create an organization that would address the needs of Asian Pacific American librarians and those who serve Asian Pacific American communities." -- About APALA

"The Black Caucus of the American Library Association serves as an advocate for the development, promotion, and improvement of library services and resources to the nation's African American community; and provides leadership for the recruitment and professional development of African American librarians." -- About the Black Caucus of the American Library Association

"Chinese American Librarians Association (CALA) started in 1973 as Mid-West Chinese American Librarians Association, a regional organization in Illinois. A year later, Chinese Librarians Association was formed in California in 1974. In 1976, Mid-West Chinese American Librarians Association was expanded to a national organization as Chinese American Librarians Association. By 1979, CALA had five chapters in Northeast, Mid-West, Atlantic, Southwest and California respectively. Chinese American Librarians Association and Chinese Librarians Association were merged in 1983. The merged organization retains CALA's English name and Chinese Librarians Association's Chinese name 華人圖書館員協會." -- About CALA

"CARL's purpose, as stated in its constitution, is ". . . to provide opportunities for the professional growth of its members by conducting workshops and arranging programs; to encourage the exchange of ideas and information relating to library cooperation and development; to disseminate educational information oriented to those working in academic and research libraries; and to support and, when appropriate, participate in programs of other regional and local organizations in California in order to promote and improve library service to the academic and research community." -- Mission CARL

"CLA is the Community for California Libraries

CLA provides leadership for the development, promotion, and improvement of library services, librarianship, and the library community. We help members excel in a fast-changing job market. We're a resource for learning about new ideas and technology, and we actively work to influence legislation affecting libraries and librarians." -- CLA Mission Statement

"CSLA advocates for excellence in school library programs, develops leaders in the school library field, and collaborates with other educational leaders to ensure that all California students are effective, responsible users and creators of ideas and information." -- CSLA Mission Statement

"The Library and Information Technology Association is the leading organization reaching out across types of libraries to provide education and services for a broad membership. The membership includes new professionals, systems librarians, library administrators, library schools, vendors and anyone else interested in leading edge technology and applications for librarians and information providers. [...]" -- About LITA

"[...] The Library Leadership and Management Association (LLAMA), a division of the American Library Association, can help you acquire the skills and knowledge that will enable you to become a leader in your profession. In tune with ever-changing technological, political, economic, and cultural conditions, LLAMA equips library professionals with a variety of dynamic tools for building strong libraries and successful careers. Our resources are tailored to professionals of diverse cultural backgrounds and all levels of library staff in all types of libraries." -- Join LLAMA

The Medical Library Association is a robust community where medical librarians can connect with other colleagues and learn about the "latest tools and education in health information management, research, and practice", and become a leader within the medical librarian profession. -- MLA Membership.

MLGSCA iis a chapter of the Medical Library Association serving Southern California (south of Fresno) and Arizona. Join approximately 300 health science librarians and information professionals to network, promote continuing education, assist in "developing library resources", and "faciliatate cooperation among medical and allied health science libraries." -- Introduction to MLGSCA

"The Public Library Association (PLA), with more than 9,000 members, is one of the fastest growing divisions of the American Library Association (ALA), the oldest and largest library association in the world. Founded in 1944, PLA is a member-driven organization that exists to provide a diverse program of communication, publication, advocacy, continuing education, and programming for its members and others interested in the advancement of public library service." -- About PLA

"Established in 1971 as an affiliate of the American Library Association (ALA), REFORMA has actively sought to promote the development of library collections to include Spanish-language and Latino oriented materials; the recruitment of more bilingual and bicultural library professionals and support staff; the development of library services and programs that meet the needs of the Latino community; the establishment of a national information and support network among individuals who share our goals; the education of the U.S. Latino population in regards to the availability and types of library services; and lobbying efforts to preserve existing library resource centers serving the interests of Latinos." -- About REFORMA

"The Reference and User Services Association is responsible for stimulating and supporting excellence in the delivery of general library services and materials, and the provision of reference and information services, collection development, readers’ advisory, and resource sharing for all ages, in every type of library." -- About RUSA

"The Special Libraries Association (SLA) is a nonprofit global organization for innovative information professionals and their strategic partners. SLA serves more than 9,000 members in 75 countries in the information profession, including corporate, academic and government information specialists. SLA promotes and strengthens its members through learning, advocacy, and networking initiatives." -- About SLA

"On February 1, 2009, Friends of Libraries U.S.A. (FOLUSA) and the Association for Library Trustees and Advocates (ALTA) joined forces to become an expanded division of ALA known as the Association of Library Trustees, Advocates, Friends and Foundations, now United for Libraries. Through this partnership, United for Libraries brings together libraries’ voices to speak out on behalf of library services and free public access to information. United for Libraries is a national network of enthusiastic library supporters who believe in the importance of libraries as the social and intellectual centers of communities and campuses. No one has a stronger voice for libraries than those who use them, raise money for them, and govern them. By uniting these voices, library supporters everywhere will become a real force to be reckoned with at the local, state, and national levels." -- About United for Libraries

The Young Adult Library Services Association (YALSA) is a division of the American Library Association. YALSA is a "national association of librarians, library workers and advocates whose mission is to expand and strengthen library services for teens, aged 12-18. Through its member-driven advocacy, research, and professional development initiatives, YALSA builds the capacity of libraries and librarians to engage, serve and empower teens." -- About YALSA