He had a practice of freeing slaves as adults after a period of service .
Of the seven Founding Fathers , the northerners Benjamin Franklin and John Jay both owned slaves whom they freed , and Jay founded the New York Manumission Society .
Benjamin Franklin had a practice of freeing slaves as adults after a period of service .
Of the seven Founding Fathers , the northerners Benjamin Franklin and John Jay both owned slaves whom they freed , and Jay founded the New York Manumission Society .