Jersey County, IL

Jersey County, Is., c. h. at Jerseyville. Bounded N. by Greene and E. by Macoupin co., S. by Madison co. and the Mississippi River, separating it from Missouri, and W. by the Illinois River, separating it from Calhoun co. Watered on the N. by a branch of the Illinois River. (Gazetteer of the United States of America, 1854)