Paid,
Hard for me to be 100% certain due to the quality of your pic, but I believe your stamp has a "C. Hensel" canx which would indicate it was used in New York, and has something to do with an import document.
I have several slightly different versions of this canx - enough I am suspecting each line was a separate handstamp ("C Hensel", and ".C.H.", and the date; "CH" for Custom House by the way) and maybe not one multi-line handstamp. Will take some work to figure it out. I have examples with different orders (date on top, date in middle, date on bottom, etc.) as well as inverted "C.H.", which is also known as ".C.H." and "C.H." without the leading period.
That said, if your copy is Hensel, here are some related scans:

Example canx from Feb 1866

Processed scan of example canx from Feb 1866

Front of 1894 cover

Back of 1894 cover

Invoice included in 1894 cover
None of this has anything to do with your original question, but may (or may not) be slightly interesting.