Antitrust and Trade Regulation laws aim to promote free competition in the marketplace. Agreements or cooperative efforts by two or more entities that affects or restrains competitors is illegal under these laws. The Sherman Act makes illegal any contract, combination, or conspiracy in restraint of trade or commerce and makes monopolies and attempts, combinations, or conspiracies to monopolize illegal. The Clayton Act regulate price discrimination, tying and exclusive dealing contracts, stock acquisition and interlocking directorates.
Tunnel City is an unincorporated community in the town of Greenfield, in Monroe County, Wisconsin, United States, named for the train tunnel just to the west which was used by the Chicago and North Western Railway (trackage now abandoned west of the tunnel) and the Chicago, Milwaukee, St. Paul & Pacific Railroad (Milwaukee Road). The existing track is owned by the Canadian Pacific Railway, and carries the Amtrak Empire Builder passenger train, though rail traffic is dominated by freight.