I scanned these images from prints which, given the era, were probably originally daguerrotypes. They depict the interior of what was then the Church of the Advent, a building which stood on the former Green Street in Boston's now-demolished West End. The congregation worshipped here from 1847 until 1862, when they moved to a vacated Congregationalist church on Bowdoin Street (now the Church of St John the Evangelist).
Notice the altar and cross, the selfsame altar and cross now enshrined in the current Advent's All Saints Chapel; and the memorial bust of Dr. Croswell alongside the reredos. History before our eyes!