Basically a promissory currency note issued by a local merchant.
Small denominational currency notes and fractional currency were at times rather scarce. Hence... State Treasuries, Local Towns/Cities, Local Banks, and even many merchants printed and issued their own notes to make change with.
It was not uncommon that they made use of sheets of unissued or blank bank note printings from others including local banks such as this was. Backs of which were typically not printed on... turn the page and reprint the new on the blank back of the old sheets, cut out and use. Not unusual to find.