2c Black receipt by Garbutt & Black, New York. Printed by the American Phototype Co. Unlisted in the Castenholz Guides to Revenue Stamped Paper.
RN-A is a small, rectangular design with rounded corners and filigree on the sides. It was used almost exclusively on receipts, although the size would have been perfect for checks. A1 is the black version. This one pays the tax on a receipt for goods. The tax in question was no longer in effect as of August 1, 1866, but receipts such as this one are known dated through the end of that year.
For an excellent primer on Revenue Stamped Paper click HERE.