Joliet is a city in Will and Kendall Counties in the U.S. state of Illinois, located 40 miles (64 km) southwest of Chicago. It is the county seat of Will County. As of the 2010 census,
the city was the fourth-most populated in Illinois, with a population
of 147,433. It continues to be Illinois' fastest growing city and one of
the fastest growing in the United States. When Joliet was first planned
in the early 1830s, it was still in Cook County. In 1836, it became the
county seat of the new Will County.