Third Religious Society Unitarian Church Postcards Third Religious Society Unitarian Church No. 2558 Postcard. Caption on front: Third Religious Society Unitarian Church, Dorchester Lower Mills, Mass. Postally unused. On verso: Pub. by Thomson & Thomson, Boston, Mass. No. 1565. Printed in Germany. Facebook Twitter Print Friendly Skills Dorchester, Lower Mills, Third Church, Third Religious Society, Unitarian Church Posted on December 9, 2022 ← Sheep at Franklin Park Lyman Memorial and St. Peters Church →