United States trademark law

A trademark is a word, phrase, or logo that identifies the source of goods or services. Trademark law protects a business' commercial identity or brand by discouraging other businesses from adopting a name or logo that is "confusingly similar" to an existing trademark. The goal is to allow consumers to easily identify the producers of goods and services and avoid confusion.

United States trademark law is mainly governed by the Lanham Act. Common law trademark rights are acquired automatically when a business uses a name or logo in commerce, and are enforceable in state courts. Marks registered with the U.S. Patent and Trademark Office are given a higher degree of protection in federal courts than unregistered marks—both registered and unregistered trademarks are granted some degree of federal protection under the Lanham Act 43(a).

United States law has protected trademarks under state common law since colonial times, but it was not until 1870 that Congress first attempted to establish a federal trademark regime. This 1870 statute purported to be an exercise of Congress' Copyright Clause powers. However, the Supreme Court struck down the 1870 statute in the Trade-Mark Cases. In 1881, Congress passed a new trademark act, this time pursuant to its Commerce Clause powers. Congress revised the Trademark Act in 1905.

In 1946, Congress passed the Lanham Act (15 U.S.C. §§ 1051–1127). The Lanham Act defines federal trademark protection and trademark registration rules. The Lanham Act grants the United States Patent and Trademark Office ("USPTO") administrative authority over trademark registration.

State law continues to add its own protection, complementing (and complicating) the federal trademark system.

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