Over the ensuing decades there was considerable political tension between the eastern and the western halves of the Cape Colony. The Eastern Cape, from its major port and urban centre Port Elizabeth, resented being ruled from Cape Town in the Western Cape and frequently agitated to become a separate colony. These separatist tensions did not completely die down until the 1870s when Prime Minister John Molteno restructured the Cape administration to meet the major eastern concerns and, in the Constitutional Amendment Bill of 1873, abolished the last formal distinctions.