Purpose -Background on library service needs that lead to the creation of regional library systems, and overview of current trends. Design/methodology/approach -Historical and philosophical overview by participating regional library system director. Findings -In Illinois, the creation of regional library systems supported the establishment of many new public libraries and service was expanded and strengthened in existing libraries. With the need for new libraries less critical, the systems have greater focus on resource sharing and library development. Originality/value -As resources for libraries continue to be strained, cooperative ventures can make scarce dollars go further.