How the Overseas Railroad and 1935 Hurricane Shaped the Florida Keys

A look at the ambitious railway that connected the Keys and the devastating storm that ended its run, forever changing the islands' landscape and future.

By Garret Merkley · Explainer · Jun 30, 2026

Branched from Florida Keys History: How These Islands Were Settled and Named

Quick take

Henry Flagler's Overseas Railroad connected the Florida Keys to the mainland, transforming isolated islands into accessible destinations.
This engineering marvel was largely destroyed by the devastating 1935 Labor Day Hurricane, a Category 5 storm.
The hurricane caused immense loss of life, particularly among WWI veterans, and ended the railroad era in the Keys.
The railroad's demise paved the way for the modern Overseas Highway, utilizing many of the original bridge foundations.

The Florida Keys, a chain of islands stretching southwest from the Florida peninsula, were fundamentally transformed by two monumental events: the construction of Henry Flagler's Overseas Railroad and the catastrophic 1935 Labor Day Hurricane. These events together ushered in an era of unprecedented connectivity and then, through devastation, reshaped the islands' infrastructure and future.

The Overseas Railroad: Flagler's Impossible Dream

Completed in 1912, the Overseas Railroad was the final extension of Henry Flagler’s Florida East Coast Railway, connecting the Florida mainland all the way to Key West. This monumental engineering feat spanned 156 miles over open water, coral rock, and mangrove swamps, utilizing 42 bridges and countless miles of fill. Before the railroad, the Keys were largely isolated, accessible primarily by boat. Flagler’s vision opened them up to tourism, commerce, and settlement, transforming Key West into a bustling port and making the entire island chain a more integral part of Florida.

The 1935 Labor Day Hurricane: Nature's Fury

On Labor Day 1935, one of the most intense hurricanes ever recorded in the Atlantic made a direct hit on the Upper Florida Keys. This Category 5 storm, with sustained winds estimated at 185 mph and a storm surge of 15 to 20 feet, caused catastrophic damage. The hurricane obliterated buildings, reshaped landscapes, and tragically claimed hundreds of lives, including many World War I veterans working on federal relief projects in the area. The storm's immense power ripped through large sections of the Overseas Railroad, tearing away tracks, bridges, and trestles.

From Railway to Highway: A New Era

The destruction of the Overseas Railroad by the 1935 hurricane marked the end of an era. The Florida East Coast Railway, already struggling financially, could not afford the extensive repairs needed. The state of Florida subsequently purchased the remaining right-of-way and salvageable bridge foundations. These foundations became the base for the ambitious Overseas Highway (U.S. Route 1), which opened in 1938. This new highway allowed automobiles to travel the length of the Keys, cementing their connection to the mainland and paving the way for the modern tourism industry.

These two events are pivotal to understanding the Florida Keys as they exist today. The railroad introduced modernity and accessibility, laying the groundwork for development. The hurricane, while devastating, forced a complete reimagining of the Keys' infrastructure, directly leading to the construction of the iconic Overseas Highway. The legacy of both the railroad's ambition and the hurricane's destructive power is etched into the landscape and history of the Florida Keys.

A Tragic Loss

The 1935 Labor Day Hurricane tragically claimed the lives of over 400 people, many of whom were World War I veterans working on federal relief projects to construct new bridges for the Overseas Railroad. This event led to significant public outcry and reforms in disaster preparedness and veteran care.

Who was Henry Flagler?

Henry Flagler was an American industrialist, a co-founder of Standard Oil, and a key figure in the development of Florida. He built the Florida East Coast Railway, including the ambitious Overseas Railroad, which opened up much of Florida to tourism and commerce.

Are any parts of the original Overseas Railroad still visible today?

Yes, many sections of the original railroad bridges, particularly the concrete foundations and some complete spans, were repurposed for the Overseas Highway. Some older, narrower bridges run parallel to the modern highway and are now used as fishing piers or walking paths, like the Old Seven Mile Bridge.

How did the 1935 hurricane affect Key West specifically?

While the hurricane caused catastrophic damage to the Upper and Middle Keys, Key West, located at the very end of the island chain, was largely spared the direct hit and extreme winds. However, its vital rail link to the mainland was severed, leading to economic hardship until the Overseas Highway was completed.

What was the peak wind speed of the 1935 hurricane?

The 1935 Labor Day Hurricane is estimated to have had sustained winds of 185 miles per hour (295 km/h) at landfall, making it one of the strongest hurricanes to ever strike the United States.

How did the Keys recover after the hurricane?

Recovery was slow and difficult. The destruction of the railroad led to a period of economic uncertainty. However, the construction of the Overseas Highway, completed just three years later, provided a new lifeline, enabling vehicular access and laying the foundation for the Keys' modern tourism economy.

Sources

National Hurricane Center (NOAA) - 1935 Labor Day Hurricane Report
Florida East Coast Railway Archives
Florida Keys Historical Society