Gilmer is a city located in Upshur County in Texas. Gilmer is the county seat of Upshur County. As of the 2010 census, the town’s population was 4,905. Thomas Walker Gilmer was the reason behind the town’s name who was the U.S Secretary of the Navy. The town was founded in 1846. The city’s educational system is being provided by the Gilmer Independent School District. As the U.S Bureau stated, the city has a total area of 4.6 square miles, all of it is land. The town is best known in particular for holding an annual event called East Texas Yamboree. It is a four-day event in the third week of October celebrating sweet potatoes as a former cash crop.