This publication summarizes the history and evolution of the Group Plan of the Claremont Colleges, a consortium of six small independent colleges in southern California. The Claremont Colleges include Pomona College; Harvey Mudd College; Scripps College; Pitzer College; Claremont McKenna College; and Claremont Graduate School. The Group Plan, the vision of Pomona College's early president James A. Blaisdell, is the organizational structure that brings these institutions together so that, while they maintain the characteristics of the small college, they also gain the advantages of a large university. The main section recounts the origins and evolution of the Colleges and the Group Plan and includes descriptions of southern California in the late 1800s; the founding of Pomona College; first formulations of the Group Plan; establishment of the Central Coordinating Corporation in 1925; the founding of Claremont Graduate School and Scripps College; the group's evolution during the 1920s and 1930s; the war years; founding of Claremont McKenna College; acquisition and holding of land; library development; affiliated institutions; addition to the group of Harvey Mudd College; the 1950s and 1960s; the addition of Pitzer College; intercollegiate committees and the Claremont University Center; and developments to the present. Closing sections briefly summarize lessons of the past and look at future challenges; list the colleges, presidents and administrators; and present a timeline of milestones in the Group Plan's development. (Contains endnotes and five references.) (JB)