I am not researching this family but thought someone could use this information.It's from the 1886 book "The History of the Susquehanna & Juniata Valleys" page 630 (huge amount of information about the John Wilson family of which this McNitt information is included (pages 628-632)
"John Wilson was born September 26, 1751, at Newton-Limavaddy, on the Row-Water, Londonderry County, Ireland.This was his home until September, 1770, when, at the age of 19 years, he emigrated to the United States, landing at New Castle, Delaware, and one month after, he settled in the Kishacoquillas Valley.........John Wilson had a brother David, who came from Ireland with him, and married a Miss Black, of Stone Valley, Huntingdon County, Pa., and lived but a short time.
He had 2 sisters who, WITH THEIR HUSBANDS, also came over to America in company with him and his brother (NB in 1770).
Elizabeth had married a Mr. __ Gettys.John and Joseph were their sons.The husband dying, she married William Fleming, and William, John, Joseph, Martin, Margaret (wife of Thomas I. Wilson) and Elizabeth(wife of Dr. William R. Finley) were their children.
Anna had married a Mr. MCNITT.Both the Gettys and McNitt families settled in Kishacoquillas Valley, and among the children of the McNitt family were Ann, who married Ephraim Clark, and after his death she became the 2nd wife of William Hazlet.Mary became the 2nd wife of her cousin, John Gettys.Margaret married John Shadle.Elizabeth and Nancy were unmarried.James was killed at a wedding, being thrown from a horse.Sarah married Hugh Laird, and died at Port Royal, Pa, March 15, 1885, in her 80th year, in the family of her daughter, Mrs. Robert A. Robison."
Hope this helps out someone.John Williamson Wilson (it is his biography in the book), grandson of the immigrant John Wilson is presumably the one who supplied all this information in 1885 (when book was written) as he was still very much alive in 1885 and a director in the Kishacoquillas Turnpike Company.