The Niagara Falls peace conference is the first well-known use of the term "ABC". On May 20, 1914, the three countries met in Niagara Falls, Ontario, Canada, to mediate between the United States and Mexico after increasing tensions over the Tampico Affair, the United States occupation of Veracruz, and developing issues that led to the Mexican Revolution. At the conference, the United States was represented by Frederick William Lehmann, a former United States Solicitor General, and Joseph Rucker Lamar, an Associate Justice of the Supreme Court of the United States.