Joanne Butler has an article, "John Witherspoon's Presbyterian Rebellion," in the Daily Caller on founding father John Witherspoon, in which she wonders a bit about the circumstances that caused him to emigrate to America.
As the question intersects with some of my family's history on my mother's side, and I have a few moments free on a Sunday evening, I can fill in some blanks for her.
In 1766, my gggggg-uncle, Rev. Samuel Finley, age 51, passed away in Philadelphia of what apparently was some form of abdominal cancer. At the time of his death, Finley was president of the College of New Jersey, now known as Princeton University.
Finley's death created a vacancy at the college that the trustees naturally were keen to fill, not least because at that time the president personally taught a substantial number of the classes. Rev. Witherspoon, who then lived in Scotland, was invited by the trustees to take the position. Despite his own personal interest, he declined, citing his wife Elizabeth's deathly fear of a transatlantic crossing.
Finley's nephew and ward, a young man named Benjamin Rush who had been raised by the Finleys jointly with his widowed mother since the death of Rush's father when he was six, and a student of Finley's both at Nottingham Academy and the College of New Jersey, felt called to assist. He borrowed money from Benjamin Franklin, an acquaintance or possibly even a friend of the family,* and went to Scotland, where Rush took up studies at the University of Edinburgh and, in a joint effort with a gentleman of historical note named Richard Stockton (whose daughter Julia Rush would later marry), sent letters to Witherspoon urging him to change his mind.
Witherspoon continued to decline the college's appointment, citing the same reason: his wife's fear of the Atlantic crossing. Rush then travelled to the Witherspoon home in Paisley (near Glasgow, Scotland) to convince Mrs. Witherspoon to emigrate. He succeeded. At the end of four days, a friend of Rev. Witherspoon wrote to Stockton in Princeton that, "to Mr. Witherspoon's great satisfaction, his wife has at last given a calm hearing to Mr. Rush, argued the Matter with him, and received a satisfying Answer to all her objections; so that now she is willing if the Doctor is rechosen... to go with him without Grudge."
The trustees then voted once again to elect Witherspoon the president of what would become Princeton University, and the rest, as they say, is history.* Benjamin Franklin had published Samuel Finley's sermons in the 1740s. There is surviving correspondence (example here) between Franklin and Finley as well as between Franklin and Finley's brother, James, as well as a letter from Deborah Franklin to her husband in 1766 informing him that "Mr. Finley is near his end and has bin as dead for several days." As late as 1774 Franklin, in a letter to Joseph Priestly, quoted a passage from an old letter of Finley's to Samuel Chandler of the Royal Society about an experiment involving inflammable air (methane escaping from the earth).