Grafton is the oldest city in Jersey County, Illinois, United States. It is located near the confluence of the Illinois and Mississippi Rivers. As of the 2010 U.S. census, the city had a total population of 674. Prior to the Great Flood of 1993, Grafton had enjoyed a stable population of nearly 1,000 residents.
Grafton is a part of the Metro-East region and the St. Louis Metropolitan Statistical Area.
Founded in 1832 by James Mason, Grafton is the oldest city in Jersey County. Described as having "a post office, one store, one tavern, and a number of families" in 1834, the area was being settled as early as 1812 when a blockhouse was built at the confluence for protection. The city was named after Mason's birthplace of Grafton, Massachusetts. Grafton was incorporated on May 16, 1907.
Grafton's population reached its peak at approximately 10,000 in the 1850s with employment opportunities coming from the local stone quarries, boat building and commercial fishing.