I just read an article at Chess Cafe entitled,  Morphy Chess Clubs - Where Are They Now? by Hanon W. Russel,
in which Mr. Russel brings up the old news about Morphy's letter to Fiske mentioning the so-called "Morphy Clubs" in Maine and Texas.

March 9, 1858

My dear Fiske:

Do not get too excited about the delay this month; it has not been in my power to forward the games sooner. Henceforward, depend upon it, the games will reach you in good time. I only send four, requesting you to insert whatever there you may see fit, as I really am at a loss to select among those I have here.
The New Orleans Chess Club has challenged Mr. Staunton for a stake of 5,000 dollars. I will send you tomorrow a copy of the letter addressed to that gentleman, together with the proposed "terms of the match" - I have received a very flattering communication from Belton Bill Co., Texas, informing me that a chess club has been established there under the name of the "Morphy Chess Club" - I understand that another "Morphy Chess Club" has been started in Maine.

Present my regards to each and every member of your club and believe me
Ever your best friend,
Paul Morphy
 

One thing I learned recently is that "Morphy Clubs" were not isolated within the U.S.

A gentleman from Holland wrote to inform me that in 1863, the University of Leiden, after studying the game of Paul Morphy that had just been published in the chess magazine, Sissa, founded the LSSG Morphy (the Leiden Morphy Chess Society) despite the fact that Paul Morphy never visited the Netherlands.