 He was said to have "detested slavery," and on at least one occasion, he purchased a mother and her child at a slave auction to grant them freedom.Matthews purchased a pipe organ for St. Patrick's from an Episcopal church in Dumfries, Virginia—likely the first organ in the District of Columbia.He acted as trusted adviser to Bishop John Carroll, whose ecclesiastical jurisdiction as Bishop of Baltimore and later as Archbishop of Baltimore, included the City of Washington and served as a liaison between the bishop and Catholic institutions and priests in Washington.