Originally published in 1993, we have split the original work into two parts and added a supplement containing the 1775 census and two hundreds (subdivisions) of the 1776 census (which were inadvertently omitted from the initial publication) and corrections. This represents a collection of data covering the period: 1773 (when the county was formed) through 1790. Volumes 1 and 2 have been extracted from the following: tax lists of 1774, 1776 (missing two Hundreds now contained in the supplement), 1778, 1783; censuses of 1776 and 1790; Dr. Archer's ledgers; orphans' court proceedings; family Bibles; estate administrations; registers of St. John's and St. George's; Quaker monthly meetings of Deer Creek and Little Falls; wills; court minutes; commercial licenses; survey certificates; land records index; marriage licenses; gleanings from various publications such as the Bulletin of the Historical Society of Harford County and other periodicals and histories; list of Non-Associators and Non-Enrollers in 1775; tombstone inscriptions; and other data drawn from the author's research and collections. This series contains over 30,000 entries.