There seems to be disagreement in the displacement of the Passaic Class Monitors. Some sources list 1335 tons. Others list 1875 tons. These same sources match for the other types of monitors.

The original Monitor was 987 tons and the Canonicus class, which followed the Passaic Class, was 2100 tons. Since the Passaic Class was closer in design and dimensions to the original Monitor, I would say 1335 tons is correct.

Anybody actually know?