In Swift & Co. v. United States, the U.S. Supreme Court unanimously upholds the Sherman Antitrust Act of 1890 and Congress’ power to ban national trade monopolies. The United States files suit against Swift & Co., a group of meat dealers who had established a set of private agreements to regulate meat pricing, and who, combined, made up 60 percent of the U.S. meat market. The plaintiff argues that the companies have violated the Sherman Antitrust Act of 1890 and have illegally conspired to control the market. Swift & Co. asserts that the law is an unconstitutional extension of Congress’ power. The Court finds that the actions of the company could adversely affect interstate markets, and therefore were under congressional jurisdiction.