In 1764, the ecclesiastical authorities saw fit to send this intrepid missionary to the Mosquito Coast, where he stayed two years, making a second visit in 1767. Toward the close of his life he retired from the Moravian sect, and entered the Protestant Episcopal Church. His death occurred at Germantown in 1785.
The journal of the first tour to the Ohio Indians (July 15-September 22, 1758), was printed in the appendix to An Enquiry into the Causes of the Alienation of the Delaware and Shawanese Indians from the British Interest (London, 1759; reprinted Philadelphia, 1867). This book was published anonymously, but was known to be the work of Charles Thomson, a prominent Philadelphia Quaker, later secretary of the Continental Congress. Thomson gives a brief preface to Post's journal, and the matter in the notes thereof is evidently by his hand; it is probable that the notes to the second journal are also by him. The first journal was reprinted by Proud, History of Pennsylvania (Philadelphia, 1798), ii, appendix, pp. 65-95, from which edition our reprint has been made. Craig also published this in The Olden Time, i, pp. 99-125, following almost verbatim the edition of Thomson and Proud. Rupp, Early History of Western Pennsylvania (Pittsburg and Harrisburg, 1846), appendix, pp. 75-98, gives the same journal. The Pennsylvania Archives, iii, pp. 520-544, also contains this journal, evidently taken from the same manuscript, with but slight variations in the spelling of proper names.
Heckewelder, Narrative of the Mission of the United Brethren (Philadelphia, 1820), pp. 55, 56, says: "To enumerate all the hardships, difficulties and dangers, Frederick Post had been subjected to on these journies, especially on the first, in the summer of the year 1758, is
