To identify the Mexican American as a member of a unique cultural group is the purpose of this history of the Chicanos. The history of the Mexican American is divided into 5 broad time periods: the Indo-Hispanic period, during which there was a blending of the Indian and Spanish cultures; the Mexican period, a time of political activity which culminated in war with the United States; a period of cultural conflict during the last half of the 19th century; a period of resurgence in the first 4 decades of the 20th century; and a period of regeneration, from World War II to the present. The 3 major subcultures of Mexican Americans within the borders of the United States today--the californio, the tejano, and the nuevo mexicano--are described in terms of the historical past. (PS)