Any history of Jews in America has the problem of defining its subject--so one cannot be certain that Dawidowicz (The War Against the Jews, etc.), in writing of the hundred years since the start of mass migration, consciously emphasized the role of national Jewish organizations because she was originally writing for the American Jewish Yearbook, published by the American Jewish Committee (AJC) and the Jewish Publication Society of America (JPSA). One assumes that she is heartfelt in her praise for the German-Jewish notables--Jacob Schiff, Oscar Straus, Louis Marshall, et al.--who established the JPSA (1881), founded the AJC (1906), and, from the pogroms into the post-WW I period, rallied in support of persecuted Jews abroad. (""All had been reared in the Jewish tradition of zedakah, righteousness, the performance of good deeds as a personal obligation to God, and they adhered to that tradition with spectacular generosity all their lives."") These and other emphases, however, limit the book--both for non-Jews and for Jews--as a popular history. There are variances of tone and treatment too. Writing of America as a promised land, Dawidowicz glows; writing of '60s upheavals, she grits her teeth. She is less than sympathetic toward 19th-century Reform Judaism's ""headlong rush into radical change,"" though this was the background of her German-Jewish cynosures; she is much pleased--it's the concluding note--by ""the vigor of the new Orthodoxy."" On her roster of organizers, there are no women--not even Henrietta Szold, founder of Hadassah. Dawidowicz's standing, and her fluency, assure that the book will be read; it also has, especially in its early pages (and intermittently throughout), an inspirational tenor. But Nathan Glazer and Oscar Handlin have both written brief treatments of the subject with more balance and less organizational stress.