The U.S. Federal Census - A nationwide population census every 10 years is required by Article I, Section 2, of the United States Constitution. The first census in 1790 did not include any of the territory that would later become Clinton Co. The second census in 1800 did include the Indiana Territory, Mississippi Territory, and the Northwest Territory but the information collected has since been lost. The 1810 census also included the Illinois Territory but half of the information (the part that would contain Clinton Co.) has also been lost.
The census records on this website have been carefully transcibed and proofed by volunteers.