His wife Mary Alsop was born in New York on October 17, 1769, and died in Jamaica, New York, on June 5, 1819. She was the only daughter of John Alsop, a wealthy merchant and a delegate for New York to the Continental Congress from 1774 to 1776. She was also a great niece of Governor John Winthrop of the Massachusetts Bay Colony. She married Mr. King in New York City on March 30, 1786, he being at that time a delegate from Massachusetts to the Congress of the Confederation then sitting in that city.