Migrations from 1900-1920 were analyzed, focusing on the overall pattern of Mexican migrations to the United States during the two decades; migrations to Texas, the major recipient of migrants during the period; and migrations into the lower Rio Grande Valley. Data were based on official registrations either entering the United States or leaving Mexico, two previous migration studies using Mexican Secretaria de Gobernacion reports and 1900 census reports, and oral history interviews with migrants into the lower Rio Grande Valley from 1900-1920. Mexican migrations during this period revealed a significant migration trend, especially when about 200,000 "illegal" entries were considered. Economic conditions in Mexico stimulated northward migration which accelerated with the turmoil caused by the 1910 Revolution. As relative stability returned, the limited economic opportunities continued to serve as a push factor. Railroad and agricultural expansion in the Southwest plus industrial occupations with the arrival of World War I acted as pull factors. Although data were incomplete, there was strong evidence to suggest that the Valley received its fair share of migration. South Texas area enjoyed geographic proximity which with the extension of railroad lines into the area and subsequent irrigation and agricultural developments attracted cheap Mexican labor. (NQA)