History
How Brooks County Was Built: Ranching, Railroad, and Tejano Roots
Brooks County was formed from Starr County in 1911. It grew from a ranching tradition that goes back to Spanish and Mexican land grants from the late 1700s.
This land was ranching country long before it became a county. Spanish and Mexican land grants in this area date to 1797. Tejano ranching families — including the Chapa and de la Garza lines — held and worked much of this land into the early 1900s. By 1980, Brooks County ranked seventh in the nation for percentage of Hispanic residents, a sign of that deep-rooted heritage.
Edward C. Lasater was a key figure in the county's modern history. He was a South Texas rancher who built up over 350,000 acres. He brought the railroad to the area in 1904. The town of Falfurrias grew at that rail stop. Lasater also started a dairy creamery in Falfurrias.
The county was formally created in 1911. It was carved out of Starr County and named for State Representative John Abijah Brooks, who pushed for its formation.
Oil was discovered here in 1935. That added another layer to the local economy and helped the county through the Depression.
The Brooks County Courthouse sits on the Falfurrias town square. It was designed by San Antonio architect Alfred Giles and built in 1914. It was restored with state funding through the Texas Historic Courthouse Preservation Program and reopened in 2010.
The Texas State Historical Association's Handbook of Texas has a full entry on Brooks County's history.
Source to confirm: Brooks County — Handbook of Texas, TSHA