Formed from Starr and Cameron counties. Created January 24, 1842. Organized April 7, 1854.

Named in Honor of Miguel Hidalgo y Costilla -- 1753-1811 Mexican Patriot

County Seat, 1852, Edinburgh, name changed February 7, 1861, to Hidalgo. Moved to present site, then called Chapin, October 12, 1908. Name changed to Edinburg, February 3, 1911.