There has been posted on ancestry.com a message, "Possible explaination of Abraham Alsdorf's presence in Gabon". This same posting has been blindly copied onto several trees on ancestry by persons not interested in seeking out proper source citations.
Therefore, it is suggested that these persons review:
"NATIONS OF CONTEMPORARY AFRICA Larry W. Bowman, Series Editor Gabon: Beyond the Colonial Legacy"
According to "NATIONS OF CONTEMPORARY AFRICA Larry W. Bowman, Series Editor Gabon: Beyond the Colonial Legacy" the American Board of Commissioners for Foreign Missions (ABCFM) had no presence in Gabon until the early 1840's. Therefore, this explanation for a marriage in Gabon is highly improbable. Especially considering the fact that the first child of Abraham ALSDORF and Peggy MORGEN, John L. ALSDORF was born on 14 Dec 1794 in New York and was christened on 11 Jan 1795 in New Hurely, Ulster, New York.