Historical carriage inside the Jackson County, Texas, Courthouse. Jackson County is a county located in the U.S. state of Texas. As of the 2010 census its population was 14,075. Its county seat is Edna. The county was created in 1835 as a municipality in Mexico and in 1836 was organized as a county (of the Republic of Texas). It is named for Andrew Jackson, President of the United States from 1829 to 1837.