On January 22, 1912, the first train from mainland Florida reached Key West through the Florida Overseas Railroad, an extension of the Florida East Coast Railway, in operation from 1912 to 1935.Until today 101 years ago, Key West is an isolated outpost reachable only by boat. Standard Oil tycoon Henry Flagler conceived the railroad that stretched more than 160 kilometers or 100 miles into open ocean, and the construction began in 1905. Similar to William Andrews Clark, who built the Los Angeles and Salt Lake Railroad that went through Las Vegas in 1905, Henry Flagler was a visionary who made remote destinations accessible to both passengers and freight.
You can read the Last Train to Key West to learn how the train services ended in September 1935.
Update: The Postcard showing a train traveling along the Florida Overseas Railroad was later sent to Brasil as US-2501260.