I asked Silvio A. Bedini, of the magazine The Professional Surveyor, if he could supply any information about Eddy and his beautiful map, and being unable to find any extensive information he did some research on his own (to be published in a coming issue of TPS in late 1998 or so).  He found that John H. Eddy, 1784-1817, identified himself as a "geographer" and ws educated in local schools but a bout with scarlet fever left him totally deaf forced him to leave school and study on his own.  His intense personal studies also otook their toll on him and he was forced to abandon them and spend time out of doors.  Among iother interests he developed a great love of geography and coresponded often with experts in the field.  At the age of 26 (c.1810) he was a serios geographer and the following year (1811) published a "Map of the Western Part of the State of New-York Showing the Route of the Proposed Canal from Lake Erie to Hudson's River" which was compiled at the request of the Canal Commissioners.  In 1814 he published a map of the NY City environs, and at about this time Gov. DeWitt Clinton asked him to compile a map showing means of communication between the Great Lakes and the Atlantic via Lake Erie and the Hudson River.  About the same time he also published a map of the Niagara River.  In 1817, shortly before his death, Eddy finished compiling a large map of New York State, which was published posthumously in 1818 (the map below).  Eddy died unexpectedly on December 22, 1817 at the age of 33 but left us one of the most beautiful and informative maps ever made of New York State.
 

See Walter W. Ristow, 1994 "The Short Life of John H. Eddy, an American 'Geographer.'" in The Map Collector (published in England?) Number 67, pages 21-23.  I have not yet found this source, but sounds interesting..