Manuel Box Bravo, county judge and civil-rights advocate, the son of David and Emma (Box) Bravo, was born at El Ambrado Ranch in Hidalgo County, Texas, on May 2, 1901. His mother came from the distinguished Box family, pioneers who settled in Houston County during the mid-1830s. Manuel, the oldest of eight children, lived and went to school near his birthplace on the banks of the Rio Grande. Though hard economic conditions forced him to quit school after completing the eighth grade, he graduated from McAllen High School in 1924. On October 24, 1919, he married Josefa Villarreal Pérez in Edinburg; they had three sons and one daughter. He worked in the Hidalgo County courthouse tax collector's office and later earned promotion to chief deputy in the delinquent tax department. In 1921 Bravo, a devout Catholic, became a charter member of the Knights of Columbus, an affiliation he maintained until his death. In the late 1920s he helped establish and served as president of the Edinburg Council of the League of United Latin American Citizens.
In 1932 he won the primary election of the Democratic party for district clerk of Hidalgo County. A year later he and his family moved to Zapata, where he engaged in several self-employed business ventures. In the November 3, 1936, general election, Bravo won by an overwhelming majority as a write-in candidate for county judge from the Partido Viejo (as supporters called the Democratic party). On January 1, 1937, he became the new county judge. He ordered county officials to begin the practice of keeping minutes of school board meetings, records of expenditures, inventories of school supplies and equipment, and auditable accounts. Despite the fact that the county was economically very poor and the educational system was in a state of neglect, his fiscal management of the school budget allowed for improvements in school facilities, approved accreditation standards for all grade levels, more certified teachers, and better playground facilities. He purchased school buses and established a veterans vocational training school with classes in vocational agriculture, distributive education, trade and industrial training, and basic preparatory courses. In 1952 Bravo successfully campaigned to get the taxpayers to approve the first bond election in the history of Zapata County.
Bravo supported Lyndon B. Johnson's farm bill of 1949, a bill that provided for telephone service to rural communities. He also solicited government assistance during droughts; in 1952 he lobbied for the establishment of a Soil Conservation Service Office for Zapata County. During the 1940s Bravo became actively involved in civil rights when he joined Alonso S. Perales and José T. Canales in condemning racial discrimination in Texas. On September 13, 1943, the Zapata County Commissioners Court approved a resolution endorsing the Good Neighbor Policy. In 1949, during the Felix Longoria affair, Bravo brought the incident to Johnson's attention. During World War II Bravo was chairman of the War Fund in Zapata County, which exceeded the established goal by 45 percent. For his loyalty, patriotism, and public spirit in a time of national crisis, the American Red Cross and the United States Treasury War Finance Committee honored him with awards.
In the 1950s the construction of the International Falcon Reservoir meant the inundation of the entire town of Zapata (the county seat of Zapata County) and other neighboring communities. Bravo fought the government for just compensation for the people. Throughout Johnson's political career Bravo was a personal friend and confidant. He retired from public office on October 1, 1957. In 1973 he served as a member of the local citizens' advisory committee to the Texas Constitutional Revision Committee. He died in Zapata on September 18, 1984, and is buried in the Zapata County Cemetery family plot.