During the Texas Revolution, Dr. James Grant (1793-1836), a Scottish-born physician, and Francis W. Johnson (1799-1884) recruited an army of volunteers to invade Mexico and capture the town of Matamoros. After Sam Houston expressed disapproval of the poorly-organized venture, many recruits left the expedition before it reached the settlement of San Patricio along the Nueces River in January 1836.
Mexican general Santa Anna, who was organizing an army to attack Texan forces at the Alamo in San Antonio, discovered the Matamoros plan and dispatched General Jose Urrea to stop the advancing expedition. Urrea's cavalry, reinforced with 300 infantrymen, crossed the Rio Grande on February 16. Meanwhile, Grant and Johnson divided their troops to hunt for horses. Johnson's men were camped at San Patricio when Urrea attacked on the morning of February 27. Johnson and 4 others escaped, while 18 texans were killed and 32 captured.
On March 2, Urrea's soldiers surprised Grant's company at Agua Dulce Creek (3. 25 miles northwest). Grant was among the 12 Texans killed; 6 were taken prisoner, and 6 escaped. The brief skirmish occurred on the same day the Texas Declaration of Independence was signed at Washington on the Brazos.