Between 1880 and 1940, the ethnic Mexican population of the American Southwest experienced tremendous dislocation, as the U.S./Mexico border region became more tightly incorporated into the global capitalist economy dominated by the United States and Western Europe. The costs of making a living off the land increased, and land loss accelerated among the rural population. Railroads brought an influx of new migrants and facilitated access to a wide variety of consumer goods, thereby expanding the potential for new business ventures in the towns and cities. Using property tax rolls, R. G. Dun Reference Books, census records, and bankruptcy case files, this paper explores the shifting landscape of business opportunities available to ethnic Mexicans as Anglo-American business culture penetrated the U.S./Mexico border region. It argues that many ethnic Mexicans were able to acquire credit and start small businesses in this period. These business owners, who formed the core of the emerging Mexican-American middle class, showed tremendous resourcefulness, persistence, and creativity, despite the limitations they faced in a competitive and often discriminatory Anglo-American capitalist economy. The geographic focus of this paper is the Lower Rio Grande Valley of Texas, a microcosm of the region where these broader trends occurred.