According to the association’s constitution adopted at that time, the purpose of the association is: [T]o cultivate the science of jurisprudence, to promote reform in the law, to facilitate the administration of justice, to elevate the standard of integrity, honor and courtesy in the legal profession, to encourage a thorough and liberal education, and to cherish a spirit of brotherhood among the members thereof.This first meeting elected Anthony Thornton as first president of the ISBA.

In 1879, the ISBA gained notoriety after it granted honorary membership to Myra Bradwell and Ada Kepley after they were denied admission to the bar on the grounds that they were women.

In the 1970s and 1980s, the ISBA lobbied successfully to have Illinois adopt a regime of no-fault divorce and for independent administration of decedents' estates.

Each section publishes a newsletter to keep its members aware of substantive changes in the field of law.

These committees study issues facing the legal community and make recommendations to the ISBA Assembly.

Members also receive E-Clips, a daily email newsletter summarizing legal news and case updates.