1861 New Jersey "On Demand" Bank Note

Hello, and help please!! I need to come up with a "guesstimate" of the fair market value of this Bank Note for an estate inventory. I'm also interested in knowing more about the history of state-issued bank notes. I couldn't find much information on the Internet.

Here's what I've learned so far (corrections welcome): It was issued by the State of New Jersey's Egg Harbor Bank rather than by the U.S. Government, although it was printed by the American Bank Note Company as were the U.S. bank notes. It was cashed in 1861, and probably printed in 1861 as well.