1. Connection of the triangulation in Tennessee with that of Northern Georgia, and extension of triangulation in Alabama towards the Gulf Coast. June 30,1890 Yale Public content 1890. 2013-10-25T14:36:43Z. 2018-12-10T19:57:37Z. U.S. Coast and Geodetic Survey. United States Coast and Geodetic Survey. English. cartographic image. Public. Alabama, Georgia, and Tennessee.