In the late 19th and early 20th century, racial tensions near the United States-Mexico border and the lower Rio Grande Valley erupted into violence as the change from ranching to commercial agriculture, shifting racial hierarchies, economic problems, the Mexican Revolution, and rising immigration increased discrimination against Mexican Americans and Mexicans and intensified conflict in South Texas. Law enforcement and vigilante groups used violence and intimidation to quell, and at times respond to, a growing movement called Revolución de Texas, which some Mexicans and Mexican Americans saw as a fight against discrimination while some in law enforcement viewed it as a threat to new Anglo migrations in the area. The section of highway between San Benito and Brownsville became the site of countless killings of prisoners without due process, including Rudolfo Muniz, one of the first victims, who was lynched there on July 29, 1915, while in the custody of local law enforcement. It is estimated that hundreds, possibly thousands, of Mexican Americans and Mexicans were killed, and many families fled Brownsville to Matamoros out of fear. A contemporary newspaper editorial called this period the Matanza of 1915, and in 1919 the Texas Legislature formally investigated state and local law enforcement practices, leading to the reorganization of the Texas Rangers. Memories of the Matanza endure through scattered records and oral tradition as a violent yet pivotal time in Texas history.