Salem is a city located in the U.S. state of Illinois. It is the county seat of Marion County. The population was 7909 at the 2000 census. Salem is the birthplace of William Jennings Bryan and his brother vice presidential candidate Charles W. Bryan, the G. I. Bill of Rights, and Miracle Whip salad dressing. It is also home to three homes on the National Register of Historic Places: the Charles and Naomi Bachmann House; the Badollet House; and the William Jennings Bryan Boyhood Home.