Biographical studies of 20 influential Chicano leaders trace Mexican American history from 1848 to the present. The book is organized chronologically by four historical periods: (1) The Cortinista Movement, 1848-1876; (2) The Teresita Movement, 1888-1905; (3) The Magonista Movement, 1904-1919; and (4) The Chicano Activists, 1920 ;o the present. Men and women from all walks of life and possessing diverse styles of leadership are represented. Juan Cortina, soldier and statesman, gives his name to the first period, when he called for Chicano unity following the Mexican American War. The second period, corresponding to Porfiro Diaz's presidency in Mexico, is named for Teresa Urrea, mystic and evangelist, who became the symbol of many campaigns against Diaz. The third period is named for the brothers Ricardo and Enrique Magona, journalists and union organizers. Chicano activists in the fourth period include Octaviano Larrazola, New Mexico governor; Emma Tenayuca, labor organizer; and Corky Gonzales, leader of student causes. The biographical sketches, drawn from primary sources as well as published documents, include personal history, family background, and anecdotal material in addition to the biographee's contributions to the Chicano movement. Footnotes follow each biography; appendices contain a chronology, an index, and notes on the photographs that illustrate the text. (JH)