A fine suggestion. May I add the following guidance:
1. Posting a scan of the entire mail piece including the back side if there is anything there. Most 1800s mail did not travel very far, such that the origin town is more likely to be near the destination town than otherwise.
2. Posting a close-up scan of the postmark.
3. Posting any scans with special lighting/contrast or digitally altered scans to emphasize the mark, such as images processed through Retroveal.
Two additional notes:
1. Jim Forte's website has a list of post offices including search capabilities by partial letter strings at:
https://www.postalhistory.com/Post_...es/index.htm2. Not every cancel is "fancy". Not every cancel is listed in the various fancy cancel books They are a small representative sampling of what the author had available to them.
All that said, your cancel looks like Williamsburgh.