The Sherman Antitrust Act of 1890, the first and most significant of the U.S. antitrust laws, outlawed trusts and prohibited "illegal" monopolies. The act applies to both domestic companies and foreign companies doing business in the United States. A trust is a relationship between businesses that collaborate through anticompetitive agreements to gain market dominance. Trusts cut prices to drive competitors out of business. "Illegal" monopolies are those that can be shown to use their power to suppress competition. A monopolist has the power to dominate markets—the ability to set the price by altering supply. Anticompetitive techniques include:

• Buying out competitors
• Forcing customers to sign long-term agreements
• Forcing customers to buy unwanted products in order to receive other goods ("Understanding Antritrust Law," 1999)

Through the passage of the Sherman Antitrust Act, Congress provided safeguards to prevent firms from merging with other firms if...