Neponset River and Dam at Mattapan Postcards Neponset River and Dam at Mattapan No. 1003 Postcard. Caption on front: Neponset River and Dam at Mattapan, Mass. Postmarked 1907 with one-cent stamp. On verso: Published by C.O. Tucker, Boston. Facebook Twitter Print Friendly Skills Dorchester, Mattapan, Neponset River and Dam Posted on November 27, 2022 ← Neponset River All Saints Church →