Any study of forces influencing public opinion, especially for the period 1789-1800, should include pamphlets as well as newspapers. In view of the very short life of the average newspaper before 1820, the difficulties of distribution, space limitations, and relative infrequency of publication, it would appear that both the newspaper and the political pamphlet were needed. By checking Charles Evans' 'American Bibliography' (Metuchen, N.J.: Scarecrow Press, 1967) and its supplement (in preparation), the author discovered over 1,000 strictly political works for the period. Apparently, during the years 1789-1800 the authors' names were concealed in two-thirds of these pamphlets. Examination of the 'Dictionary Catalogue of the Americas' (28 volumes) of the New York Public Library resulted in additions and amendments (as well as an author index) to the author's 'Political Works of Concealed Authorship in the United States, 1789-1810' (Hamden, Conn.: Shoestring Press, 1965). These additions are included with the article. 3 notes.