Mary Louise Pollock was the daughter of Carlile Pollock [1791-1845] and the granddaughter of George and Catherine Yates Pollock [c. 1760-1805]. George was one of three sons of John Pollock, of Newry, County Down, Northern Ireland who emigrated to America; the three became merchants in New York. George and his brother Carlile married sisters in the Yates family, prominent citizens in early America. The Yates/Pollock families were subjects of portraits by Gilbert Stuart, now in NGA: Mrs. Richard Yates (1940.1.4), Richard Yates (1942.8.29), Catherine Yates Pollock (1942.8.19) and George Pollock (1942.8.18). Anne Elizabeth (Betsey) Polloc, sister of George, became the second wife of Dr. William Hartigan, surgeon and professor of anatomy at Trinity College, Dublin. A portrait of Mrs. Hartigan now attributed to Carl von Breda, an artist who worked for a time in Joshua Reynold's studio, is also in the NGA. Mary Louise had a son, Henry Chiapella [1849- c. 1908].