1. Triangulation between the Hudson River and Cape Henry and Ohio River : June 30, 1882 Yale Public content 1882. 2013-10-01T17:52:25Z. 2018-12-18T20:00:22Z. U.S. Coast and Geodetic Survey, issuing body. U.S. Coast and Geodetic Survey. English. cartographic image. Public. Middle Atlantic States.