Political map of North America & the Caribbean 29 September 1858 (Mexican Reform War): In Mexico, the antagonism between the reform-minded Liberal Party (Liberal Party (Mexico)) and the Conservatives (Conservative Party (Mexico)), backed by landowners and the Catholic Church, erupted into civil war (Reform War) in 1858 when a Conservative coup overthrew the Liberal government. Despite this setback, the Liberals had popular support and control of the critical port of Veracruz, leading the Conservative regime to bankruptcy and collapse two years later.