Is there a Burlington in New York, or could this property transaction be related to the West Jersey Proprietors of Burlington, New Jersey, who held and then subdivided large tracts of land in PA and NJ? 
Could the name be Coxe?   Thomas Coxe was a land agent for William Penn in the 1680s.   Tench Coxe was a wheeler-dealer in land transactions also.  William may have been a descendant.
William Coxe 1762-1831 appears in two collections related to land transactions in NJ.    Records of the West New Jersey Society, 1732-1773, located at the New Jersey Historical Society, cite Coxe as a correspondent.  He also appears as a correspondent in the papers of the land-holding Stevens family, 1663-1959, located in Special Collections at Rutgers Univ. in New Brunswick.

Mary Prendergast