Midwestern grain farmers had to store their grain in grain elevators until the grain could be transported and sold to eastern buyers. The firm of Munn and Scott (defendant) was founded in 1862 and soon, along with a few other companies, acquired monopoly control over the rates farmers paid to store grain in Chicago. In 1871, the Illinois legislature attempted to curb the companies' power by limiting the prices they could charge, forcing the companies to lower their rates. Munn and Scott refused to comply with the law. Illinois (plaintiff) successfully prosecuted the firm for noncompliance. Munn and Scott appealed to the Supreme Court of Illinois, which affirmed the trial verdict. Munn and Scott appealed to the United States Supreme Court.