The City of Florence became Twain's favorite Italian city, despite his first experiences in 1867. Annexed by Sardinia in 1860, it was the Kingdom of Italy's first capital from 1865 to 1870, when Rome joined the kingdom.

Sam and companions arrived by train from Bergamo July 20, 1867 at 8pm. They departed by night train for Florence July 22, 1867. Mark Twain Project: Quaker City Itinerary

Bædeker Northern Italy (1877) Route 36 page 204

The Quaker City made port at Cagliari October 13, 1867 but because of cholera no one left the ship.  The ship then proceeded to Algiers.