Cameron County. Created February 21, 1848; From Nueces County; Organized August 7, 1848; Named in honor of Ewen Cameron, 1811-1843; Captain in the Mier Expedition; Shot at Queretaro; County Seat, Santa Rita 1848-1849; Brownsville, since the earliest battles of the Mexican War, and the last battle of the Civil War were fought in this county #639