The area of South Texas known as the Lower Rio Grande Valley became in the period between the U.S. Civil War and World War I one of the few regions south of the Mason-Dixon Line where racial miscegenation laws were frequently challenged. As a consequence a small but significant number of prominent black-ethnic Mexican families emerged to complicate both the Anglo-Mexican and black- white racial dichotomies so common in the rest of the nation. In the article below historian Alberto Rodriquez describes that process.
The U.S. Census of 1900 for Cameron County, Texas, which today is dominated by the cities of Harlingen and Brownsville, showed an unusual statistic. According to that census, 177 blacks formed 18 households in Cameron County. Of those eighteen households, seven or 38% were interracially married. In neighboring Hidalgo County, where the largest cities are Donna, McAllen, and Edinburg, Texas, there were 18 out of 25 families interracially married or 72% of the black population. These two counties had the highest rates of interracial marriages involving at least one black spouse in the United States at that time.
Most of the black women and men of Cameron and Hidalgo Counties migrated from the Deep South to the southern most region of Texas. These were farm families. Out of the 18 interracial households in Cameron County, nine families (50%) owned their land while nine families rented. In Hidalgo County, 10 out of 25 or 40% of the interracially married couples owned land. If blacks acquired land in South Texas, it happened in one of two ways. Either they had economic success which provided the resources to purchase land, or they married into the landed ethnic Mexican families of South Texas.
These interracial marriages along the Lower Rio Grande Valley for the most part were black men marrying ethnic Mexican women or first generation Tejanas (Texas-born women of Mexican descent). Typical of these marriages was the union of Louis and Angle Rutledge of Hidalgo County. Louis Rutledge was