Lowers the voting age to 18 years. Proposed March 23, 1971; ratified July 1, 1971, 3 months later. The Twenty-sixth Amendment to the United States Constitution establishes a nationally standardized highest permissible minimum age of 18 for participation in state and federal elections. It was proposed by Congress on March 23, 1971, and three-fourths of the states ratified it by July 1, 1971. Wiki link