THIS BOOK IS AN ANALYSIS OF THE ASSIMILATION AND RESIDENTIAL SEGREGATION PATTERNS OF TEN EUROPEAN IMMIGRANT GROUPS (FIRST AND SECOND GENERATION) IN TEN MAJOR AMERICAN CITIES FROM 1910 TO 1950. DATA WERE GATHERED FROM THE DECENNIAL UNITED STATES CENSUSES. IN EACH CITY GROUPS WERE SELECTED ON THE BASIS OF THEIR RELATIVE NUMERICAL IMPORTANCE THEREIN. THE STUDY CONSIDERS SUCH FACTORS AS THE RELATIONSHIP BETWEEN SEGREGATED RESIDENTIAL PATTERNS AND THE IMMIGRANTS' ABILITY TO SPEAK ENGLISH, SOCIOECONOMIC STATUS, LENGTH OF RESIDENCE, HOUSING, INTERMARRIAGE, MOTIVATION TO ACQUIRE CITIZENSHIP, AND OCCUPATIONAL STATUS AND MOBILITY. THE RESIDENTIAL ISOLATION OF NEGROES FROM WHITE IMMIGRANT GROUPS IS BRIEFLY EXAMINED. INDEXES OF DISSIMILARITY WERE USED TO DETERMINE THE DEGREE OF A GROUP'S RESIDENTIAL SEGREGATION FROM OTHER IMMIGRANT GROUPS AND NATIVE WHITES IN A CITY. EXTENSIVE STATISTICAL DATA ARE INCLUDED. THIS DOCUMENT IS PUBLISHED AT $5.50 BY THE FREE PRESS, 866 THIRD AVENUE, NEW YORK, NEW YORK 10022. (LB)