Mercitilli County was founded in 1874 by Clok settler James Fellonis Markson and his wife. The Marksons settled there and started a family. For years, the county held the title of "Most Rural County in Salviana". In 1932, more people moved to the county and started building cities and towns. In 1940, the Cloks were forced out of the cities and into rural areas of the county.