Information is from Mary Veldran DeWitt’s “The DeWitt Genealogy: Descendants of Tjereck Claessen DeWitt of Ulster County, New York.”
Further notes from Andries DeWitt Bible (not available in print, but see photos at link above and on Andries’ page), courtesy of the Matthew Ten Eyck DeWitt Family Collection.
Baptismal and Marriage Registers of the Old Dutch Church of Kingston, Ulster County, New York (formerly named Wiltwyck, and often familiarly called Esopus or ’Sopus), for One Hundred and Fifty Years from their commencement in 1660. Transcribed and edited by Roswell Randall Hoes, Chaplain U.S.N., corresponding secretary of the New York Genealogical and Biographical Society, etc. New York 1891; available today from Higginson Book Co., Salem, Mass., 508-745-7170. Detailed information about baptisms has been filled in through the end of 1687, marriages through 1701. More information is available. Records begin 1660. Other baptisms may have taken place in Hurley and other locations nearby; also from time to time itinerant ministers would travel through and perform various rites, not always entered in the books.
This is available online at archive.org.
Thomas Grier Evans, The De Witt Family of Ulster County, New York (reprinted from the New York Genealogical and Biographical Record, October 1886), New York: Trow’s Printing and Bookbinding Co., 201-213 East Twelfth Street, 1886. Available online from archive.org.
Evans’s work, reprinted in 1886 up to the point where it left off in Volume XVIII of the Record, was continued in 1890 (Volume XXI, commencing on p. 185) with additional names and family numbering. The reprinted portion includes names of descendants to the fourth generation; the extension shows their descendants, the fifth generation, with considerable further biographical information on some. This later addition to Evans’s work (he also published details on other families that intermarried with DeWitts in Ulster County, including Crispells, Bruyns, and others) extended into Volume XXII (January 1891, pp. 3-6). (I include here links to some publicly available copies of the individual issue and articles from the Record, but a better way to get access to it and a wealth of other genealogical resources, in addition to supporting genealogical research in general, is to join the NYGBS itself.)
Marbletown, New York, baptism records at archive.org.
Invaluable church records for this line are in Minisink Valley Reformed Dutch Church Records, 1716-1830, from the New York Genealogical and Biographical Society
(Vol. V in their “Collections” series, originally published in 1913, and re-released (in cooperation with the Genealogy Society of Sussex County, New Jersey) in 1992 by Heritage Books, Bowie, Maryland (ISBN 1-55613-556-4), available today on archive.org and in other online repositories. Thanks to Sarah DeWitt for this link.
Note that Dingman Versteeg, who was involved in preserving the old town council minutes from Kingston, was also involved in transcribing these records (free registration required).
The introduction to the NYGBS volume is worth reading for background in disentangling the intertwining connections among the nearby communities, including some hints about where missing family graves may be found.
Napanoch Church Records should be somewhere (possibly titled Wawarsing). And sure enough, the Kerckelick Protocoll voor de Gemeynte van Wawarssinck (Church Record for the Congregation of Wawarsing), starting with the church’s dedication on 20 October 1745, was collected and transcribed separately by both the Holland Society and the New York Genealogical and Biographical Society, which published the results in the Record, Volume 50, 1919 (available at archive.org), starting on Page 7 with a brief history of the church and of the transcription efforts. The NYGBS transcription is edited by Royden Woodward Vosburgh; he refers in his introduction to Dingman Versteeg’s 1898 transcription for the Holland Society. (Also worth a look: The Wikitree One Place Study of Wawarsing Hamlet, which gives a good concise history of the place with genealogy in mind, mentioning family names, some historical points of interest, and neighboring villages.)
The transcription was extensive, running through all four issues of the Record in 1919 and on into Volume 51 in 1920. The very first baptism recorded in the record is that of MVDW 135 Ruben, the son of Egbert DeWitt (MVDW 24, one of the founders of the congregation) and Maria Nottingham. Wawarsing church records can be found in New York Genealogical and Biographical Society Record, Vols. 50 and 51 (1919 and 1920), transcribed and edited by Royden Woodward Vosburgh (thanks WikiTree for this note).