Harrison County was established in 1839 and was named after Texas Revolutionary Jonas Harrison. This area was settled by planters from the Southern States who developed the area mainly for cotton production. After the Civil War, the county shifted from an agricultural-focus to industry-focus when the Texas and Pacific railway established its headquarters in Marshall. In 1928, oil was discovered in the county, spiking a boom for its exploitation and processing. Today, most of the crops grown in Harris county is used for forage for supporting its large cattle industry.