Vol 13, No 24, June 13, 2010, "Quiz Answer: How Many Different Mint Buildings?"
The E-Sylum at its best, aggregating the knowledge from its more than 1000 subscribers in order to answer a deceptively difficult question.

That was a great question, and it is subject to interpretation. Here is my answer, even though the actual buildings were not authorized by the U.S., in a couple cases.

1. First Philadelphia Mint
2. Second Philadelphia Mint
3. Third Philadelphia Mint
4. Fourth Philadelphia Mint
5. Denver Mint
6. First San Francisco Mint (beginning in 1854)
7. Second San Francisco Mint
8. Third San Francisco Mint
9. West Point Mint
10. Charlotte Mint
11. Dahlonega Mint
12. New Orleans Mint
13. Carson City Mint
14. The Dalles, Oregon
15. The Denver Mint of Clark, Gruber was intended to be operated as a United States Mint, although the government produced no actual coins at that facility.
16. The U.S. Assay Office in San Francisco, operated by Augustus Humbert absolutely qualifies
17. The "Fugio" Mint where the 1787 Fugio cents were produced.

I have attached illustrations of 16 of those 17 listed. The combination of "building facilities" and "authorized" pose the challenge. Does that mean "authorized to build," or "authorized to occupy?"

For example, the San Francisco Assay Office occupied by Augustus Humbert when the US Assay gold coins were produced may have been a previous structure that the government authorized Humbert to occupy, rather than a new building constructed for the purpose.

Also, we could add "Harper's cellar" to the list for the 1792 half dismes, if that is where they were struck. Then there are the Nova Constellatio patterns. Continental dollars (or whatever they are) could also be included.

If the Charlotte Mint burned down before coinage began (and I have never heard of that before) was rebuilt, was it also reauthorized? If not, then it doesn't count as two, only as one. The only southern mint that burned down, to the best of my knowledge, was Dahlonega, but that was long after coinage ended.

Click here to view all of Mark's U.S. Mint building illustrations on our Flickr archive (Many thanks to Mark and also to John Salyer for uploading these): www.flickr.com/photos/coinbooks/sets/72157624261506804/