Terrell,

Although he does not provide an answer to your question regarding
the origin of the name St. Petersburg, Paul Sorrentino draws some
interesting parallels between Twain's "The Belated Russian Passport"
and his 1902 trip to Hannibal.  Sorentino's article "Mark Twain's 1902
Trip to Missouri" is in the _Mark Twain Journal_, Volume 38, No. 1,
Spring 2000.  "The Belated Russian Passport" is in the Oxford edition
of _The $30,000 Bequest and Other Stories_.

Barb