Beginning with the Sherman Act in 1890 which banned, "every contract, combination …, or conspiracy, in restraint of trade" price fixing by the manufacturer was held to be illegal.
Miles Medical Co. v. John D. Park and Sons, 220 U.S. 373 (1911), the United States Supreme Court affirmed a lower court's holding that a massive minimum resale price maintenance scheme was unreasonable and thus offended Section 1 of the Sherman Antitrust Act.
Subsequent decisions characterized Dr Miles as holding that minimum resale price maintenance is unlawful per se - that is, without regard to its impact on the marketplace or consumers.
Colgate's progeny in 1984 further built upon this right in Monsanto Co. v. Spray-Rite Service Corp., stating that, "under Colgate, the manufacturer can announce its re-sale prices in advance and refuse to deal with those who fail to comply, and a distributor is free to acquiesce to the manufacturer's demand in order to avoid termination".
Aside from suggesting retail prices or having the reseller act as an agent of the manufacturer and sell the goods on consignment, until the 2007 Leegin Creative Leather Products, Inc. v. PSKS, Inc. decision a Unilateral Policy was the only way that a manufacturer could directly influence a reseller's retail price without subjecting itself to per se liability for price fixing.