It was the second San Francisco Mint that survived an earthquake in 1906, not the third as you show in The E-Sylum. Based on your response about the columns of the (second) third Philadelphia Mint, I suspect that some people find this area confusing.

Regarding Mark Borckart's list of mint buildings, allow me to comment regarding the following from Mark and to update my total to 18 facilities.

Mark wrote:

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.

Also, we could add "Harper's cellar" to the list for the 1792 half dismes...

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.

[1] Re the Denver Mint: If the authorizing bill of 19 December 1861 did indeed authorize the striking of coinage, then Mark is surely correct. The Government bought the Clark & Gruber private mint building and equipment for $25K and opened it 24 September 1863 as a US Mint & Assay Office. Since 'Mint' is in the title, it probably should have been included in the list. So, 2 facilities for Denver.

[2] If Humbert's 1851 SFO assay office (Moffat & Co) was titled as a provisional mint, as noted in the Red Book, I guess the $50 pieces should be considered official coinage. Thanks, Mark.

[3] I don't count the 1787 Fugios because there was as yet no U.S. Government and Congress under the Constitution. But I should have framed my question more carefully.

[4] Harper's Cellar wasn't a facility authorized by Congress, was it? It was just convenient.

[5] The Charlotte Mint was authorized 3 March 1835, minted coins 1838-1844, burned down in 1844, rebuilding was authorized by Congress 3 March 1845, and minting resumed October 1846. So I took it as two facilities.

On the night of July 27, 1844, it was nearly destroyed by fire, which occurred in the coining room, and nearly consumed the entire building. The machinery was seriously injured but the records being stored in the vault, were not injured. Mr. Caldwell, the superintendent, reported that evidently the fire was the work of a thief, as his living apartments had been entered and articles stolen.

The present building was authorized by an act of March 3, 1845, and was completed at a cost of $31,572.97, and occupied in 1846, and used for coinage purposes until May 20, 1861, when North Carolina entered the Confederacy and operations were suspended. The building was used during the Civil War as a Confederate hospital.