Antonio Rivas was the first known rancher on the land in 1765.
The county still has a considerable ranching community.

On March 27, 1849, Capt.
Sidney Burbank established Fort Duncan, previously known as Camp Eagle Pass, on a site two miles (3 km) north of the ford at Adjuntos Pass.

General William Leslie Cazneau, credited several years earlier with burying the Alamo casualties with full military honors, began ranching in the area around 1850.
 He partnered with Irish-born San Antonio banker and county settler John Twohig to lay out a plan of Eagle Pass in 1850.
That same year, a Mexican garrison established Piedras Negras across the border.

Freight operator Friedrich Wilhelm Carl Groos secured a contract to haul supplies for the army at Fort Duncan.
At his urging, several early settlers of Eagle Pass were emigres of the Mexican river villages and missions of San Juan Bautista, San José, Santo Domingo, San Nicolás, La Navaja, and San Isidro.

Emigres Refugio and Rita Alderete de San Miguel used the profits of their freighting business to establish a large-scale cattle, sheep, and horse ranch on Elm Creek in 1853.
They were joined in ranching operations by stranded pilgrims on the California Gold Rush trail and discharged Fort Duncan soldiers.
Among these was Infantry veteran Jesse Sumpter, who also worked at many odd jobs before becoming sheriff in the newly formed Maverick County.

Landscape pioneer Frederick Law Olmsted visited Eagle Pass in 1854, and noted the many slave hunters and runaway slaves residing in Piedras Negras, as well as the many saloons and gambling houses, which catered to Fort Duncan's soldiers and other unsavory characters.

In 1855, Texas Governor Elisha M. Pease authorized a raid into Mexico.
An international incident was brought about by James H. Callahan and William R. Henry, whose pursuit of Lipan Apache raiders and runaway slaves into Mexico ended in the looting and torching of Piedras Negras, after an encounter with Mexican forces at La Marama on the Río Escondido.
Antonio Rivas was the first known rancher on the land in 1765. The county still has a considerable ranching community.
On March 27, 1849, Capt. Sidney Burbank established Fort Duncan, previously known as Camp Eagle Pass, on a site two miles (3 km) north of the ford at Adjuntos Pass.
General William Leslie Cazneau, credited several years earlier with burying the Alamo casualties with full military honors, began ranching in the area around 1850.  He partnered with Irish-born San Antonio banker and county settler John Twohig to lay out a plan of Eagle Pass in 1850. That same year, a Mexican garrison established Piedras Negras across the border.
Freight operator Friedrich Wilhelm Carl Groos secured a contract to haul supplies for the army at Fort Duncan. At his urging, several early settlers of Eagle Pass were emigres of the Mexican river villages and missions of San Juan Bautista, San José, Santo Domingo, San Nicolás, La Navaja, and San Isidro.
Emigres Refugio and Rita Alderete de San Miguel used the profits of their freighting business to establish a large-scale cattle, sheep, and horse ranch on Elm Creek in 1853. They were joined in ranching operations by stranded pilgrims on the California Gold Rush trail and discharged Fort Duncan soldiers. Among these was Infantry veteran Jesse Sumpter, who also worked at many odd jobs before becoming sheriff in the newly formed Maverick County.
Landscape pioneer Frederick Law Olmsted visited Eagle Pass in 1854, and noted the many slave hunters and runaway slaves residing in Piedras Negras, as well as the many saloons and gambling houses, which catered to Fort Duncan's soldiers and other unsavory characters.
In 1855, Texas Governor Elisha M. Pease authorized a raid into Mexico. An international incident was brought about by James H. Callahan and William R. Henry, whose pursuit of Lipan Apache raiders and runaway slaves into Mexico ended in the looting and torching of Piedras Negras, after an encounter with Mexican forces at La Marama on the Río Escondido.
Maverick County, Texas