Cass County lies in the upper northeast corner of Texas, situated against the northwest border of Louisiana. Originally inhabited by Caddo Indians,they were exeplled by the Delaware, Shawnee, and Kickapoo tribes in the 1820s. French settlers made first contact in territory in the 1680s and 1690s. French settlement became permanent in 1719 with the establishment of Le Poste des Cadodaquious by Bénard de La Harpe. Primarily used for agriculture, the land contains rich soil used to grow corn, raise cattle and other animals, and natural resources such as oil and gas.
Native Americans began to leave the land in the 1830s after suffering from diseases and threats of expulsion. Western Europeans began to settle onto the land. Cass County was partitioned from parts of Bowie County in 1846 and named after Michigan Senator Lewis Cass, a supporter of Texas' annexation. During the Civil War, county officials tried several times and temporarily succeeded in changing the county's name to Davis, after Confederate President Jefferson Davis. The county approved secession from the Union but did not actively participate in military operations.
After the war, Cass County's economy was propped up by sharecroppers and farmers through the production of corn and cotton, and later through timber and oil reserves. However, the economy stagnated and did not develop much beyond agriculture. After the market recovered, land distribution increased and farming became the primary source of income, and manufacturing plants would later supplant farming. Later in the century, the timber industry added to the overall prosperity of Cass County.
Text: http://www.tshaonline.org/handbook/online/articles/hcc07 Handbook of Texas Online, Texas State historical Association