History of the Overseas Railroad & Seven Mile Bridge

The Overseas Railroad and the iconic Seven Mile Bridge represent one of the most remarkable engineering feats in American history. Spanning the stunning stretch between mainland Florida and Key West, this ambitious project symbolized progress, determination, and innovation. Today, remnants of this engineering marvel continue to attract tourists and history buffs alike, serving as a reminder of the bold vision of Henry Flagler and the indomitable spirit of early 20th-century America.

The Dream of Henry Flagler

Henry Morrison Flagler, a wealthy oil tycoon and co-founder of Standard Oil, was the driving force behind the development of Florida’s east coast. By the early 1900s, he had already built a network of hotels and the Florida East Coast Railway (FEC) that reached as far south as Miami. But Flagler had his sights set further—on the remote island of Key West.

At the time, Key West was a bustling port city with trade links to Cuba and Latin America. Flagler believed connecting it to the mainland would enhance commerce and travel, further boosting Florida’s economic potential. Thus, the idea of the Overseas Railroad—dubbed the “Eighth Wonder of the World”—was born.

Building the Impossible

Construction of the Overseas Railroad began in 1905. The project was monumental. Engineers and workers had to deal with scorching heat, hurricanes, labor shortages, and the challenges of building over open ocean and marshland. The most daunting section was the Seven Mile Bridge, linking Knight’s Key to Little Duck Key.

Instead of traditional roadbed construction, engineers had to create miles of bridges and viaducts. Massive concrete piers were poured in the shallow waters of the Keys, and steel trusses and girders connected them. Supplies were often brought in by sea, and housing for workers was constructed on floating barges and temporary camps.

The Seven Mile Bridge

The Seven Mile Bridge, which opened in 1912, became the most iconic segment of the Overseas Railroad. At the time, it was one of the longest bridges in the world. The structure extended more than seven miles across the Florida Straits, providing a direct rail link to Key West. The sight of a locomotive gliding over the open sea was both surreal and breathtaking—a testament to the era’s bold ambition.

Inauguration and Operation

On January 22, 1912, Henry Flagler—by then 82 years old and wheelchair-bound—rode aboard the first official train into Key West. It was a triumphant moment. The trip had taken nearly a decade to complete and had cost more than $50 million (an astronomical sum at the time), but the result was a railway line like no other.

The Overseas Railroad served not only passengers but also freight, including mail, pineapples, cigars, and other goods from the Caribbean and Latin America. It brought new life to the Keys, boosting tourism and trade, and forever changing the character of the region.

Tragedy Strikes: The 1935 Labor Day Hurricane

The Overseas Railroad operated for just over two decades before disaster struck. On September 2, 1935, one of the most powerful hurricanes in U.S. history devastated the Florida Keys. With winds exceeding 185 mph and a massive storm surge, the hurricane destroyed large portions of the railroad. Hundreds of people, including many World War I veterans working on a federal relief project, were killed.

The FEC Railway deemed it too expensive to rebuild. Instead, the State of Florida bought the remaining infrastructure and repurposed it into the Overseas Highway—a roadway that followed the original railroad bed and bridges.

Transformation into the Overseas Highway

In 1938, the first highway opened along much of the old railroad route, allowing automobiles to travel all the way to Key West for the first time. The original Seven Mile Bridge was adapted for vehicular traffic, with concrete added over the rail tracks.

Later, in the 1970s, a more modern bridge—what we now call the new Seven Mile Bridge—was built alongside the historic one. The new bridge, completed in 1982, is taller and more resilient, designed to withstand hurricanes and handle higher traffic volumes.

The old Seven Mile Bridge still stands, mostly intact, and has been converted into a scenic pedestrian and cycling path known as the Old Seven Mile Bridge Trail. It's especially popular with tourists visiting Pigeon Key, a small island that once served as a work camp for railroad employees.

Legacy and Preservation

Today, the legacy of the Overseas Railroad and Seven Mile Bridge lives on in local museums, historical sites, and the collective memory of the Keys. The Key West Museum of Art & History at the Custom House features exhibits about Flagler and the railroad. On Pigeon Key, visitors can explore restored buildings from the construction era and learn about the daily lives of the workers who built the railroad.

The story of the railroad is also commemorated during various festivals and local events, where its daring construction and eventual transformation into the Overseas Highway are celebrated.

Cultural Impact

The Overseas Railroad did more than just connect cities; it connected cultures. It brought new ideas, people, and economic opportunities to the Florida Keys. It spurred the development of tourism, which remains the backbone of the region’s economy. Even today, the romantic vision of a train journey over the sea continues to inspire books, documentaries, and films.

Ernest Hemingway, who lived in Key West during the height of the railroad’s operation, even referenced the project in his writings, noting the changing face of the island and its growing link to the outside world.

Conclusion

The history of the Overseas Railroad and the Seven Mile Bridge is one of vision, perseverance, and transformation. From the grand ambitions of Henry Flagler to the tragic hurricane that brought the railroad’s end, the story is rich with drama and innovation. What was once a daring rail link across the ocean is now a scenic highway, bringing millions of visitors to the Florida Keys each year.

As you drive or bike across the Seven Mile Bridge, you’re not just traversing a stretch of road—you’re riding across a living monument to human ingenuity, resilience, and the relentless pursuit of connection.