President Trump signed an executive order on August 27, 2026, directing the Interior Department and the Board on Geographic Names to rename Lake Ontario 'Lake America' within 30 days, updating the federal Geographic Names Information System and removing all references to the old name from government documents, maps, and contracts. The order frames the change as recognition of American investment in and historical reliance on the Great Lakes system. It arrived days after U.S.-Canada trade negotiations collapsed and new 50% U.S. tariffs on roughly $20 billion in Canadian goods took effect, with Canada announcing matching counter-tariffs set to begin September 8. The action follows the same legal template as Trump's January 2025 executive order renaming the Gulf of Mexico the 'Gulf of America.' As a Congressional Research Service analysis of that earlier order explained, federal naming decisions apply only to U.S. agencies and cannot bind other countries, private mapping companies, or non-federal entities. The name 'Ontario' derives from an Indigenous Iroquoian word — recorded in Wendat and related languages — meaning 'great lake' or 'lake of shining waters,' and predates both nations. Canadian Prime Minister Mark Carney said Canada will continue using 'Lake Ontario.'