The Florida Keys remained underwater until around 100,000 years ago, as tiny coral polyps slowly built the ancient colonies that form the basis of many of these islands.
When the Upper Keys were forming, sea level was about 35 feet higher and the southernmost point of Florida was a hill west of Lake Okeechobee.
As the Upper Keys Historical Preservation Society website at www.keyshistory.org explains Keys geology, there is said to have been an ancient reef about 500 million years ago.
Two to three million years ago, shifting sand formed massive shoals over the ancient ocean bottom. The tops of these sand shoals received enough sunlight, being no deeper than 40 feet, for corals (carnivorous animals with hard skeletons) to grow.
The major reef-building corals were elk horn, stag horn, brain and star corals. As they died, their skeletons remained and formed structures large enough to become islands. The spaces between these large corals were filled in by many other calcium carbonate organisms and plants, including sea fans, mollusks, coral debris, with the most prolific being a green algae called “Halimeda.”About 100,000 years ago the earth’s temperature cooled, the two polar ice caps began to grow, and sea level dropped – exposing the coral reefs. Florida’s coast, especially along the Gulf, would have extended outward many miles from the present shoreline. One could have walked to the outer reefs and even to the Dry Tortugas. Most of the Keys may have been connected, and the Everglades became a vast savanna with camel, bison and mammoth.
Then, about 30,000 years ago, the polar caps began to melt and sea level began to rise. New coral began to grow in some of the newly submerged areas.
The Upper Keys were higher and generally longer than the Lower Keys, with fewer channels to impede coral growth. For this reason, there are more outer reefs in the Upper Keys. The flow was so significant that the Lower Keys are aligned more north and south than the Upper Keys. Geologists have named this fossilized layer of coral growth Key Largo Limestone. The Upper and Middle Keys are primarily formed of Key Largo Limestone. Two of the best examples of this formation are the walls of the Marvin D. Adams Waterway at Mile Marker 103 and the Windley Key Quarry at Mile Marker 84.5. Today Bahia Honda at Mile Marker 37 is the southernmost key on which this coral structure is evident.
This formation lies beneath the oolitic formations (called Miami Oolite) to the north on the mainland and to the south, in the Lower Keys. Big Pine Key marks the beginning of the oolite keys. Oolite is composed of compacted small egg-shaped deposits of calcium carbonate.
Turning to the history of the people inhabiting these islands, as the islands rose from the waters, several Native American tribes nomadically visited the area. The Spanish, led by Ponce de Leon, arrived in 1513. Early homesteading settlers (other than those stranded here by shipwrecks) generally migrated from the Bahamas as early as the 1820s. Before the lighthouses were constructed, wrecking became the principal occupation, especially in Key West.
These pioneers were known as Conchs (pronounced konk), after the snail-like animal that lives in a gorgeous shell. Their descendants – at least those actually born in the Keys – are still known as Conchs. Long-time locals are sometimes referred to as “fresh-water Conchs.”
The culinary tastes of Keys residents have certainly changed, as have fishing regulations. The early pioneers corralled manatees (also known as sea cows), turtles (in turtle kraals) and harvested conch.
By the time of the brief English occupation of Florida, starting in 1763, the Calusa Indians had more or less disappeared from the Keys. American occupation of Florida in 1821 led to deployment of a fledgling U. S. Navy Pirate Fleet the following year, which eventually chased the pirates from the area.
Monroe County, named after President James Monroe, was formed in 1823 and covered south Florida from Charlotte Harbor to the Hillsboro inlet, with Key West as county seat. A small part of the south Florida mainland remains within Monroe County to this day.
In 1831, ten-acre Indian Key was settled by the illustrious Capt. John Jacob Housman, who had years earlier sailed from New York harbor, without permission, on his father’s tall ship, William Henry. Eventually he reached Key West’s port and, after several controversial years there, left with his wife and family to establish a small colony on Indian Key. The first post office on Indian Key opened in May 1833.
In 1836, to the understandable displeasure of Key West residents, Indian Key was named the first seat of Dade County, which spanned Bahia Honda Key to Cape Sable to Lake Okeechobee and along the Hillsboro River to the Atlantic Ocean. (Today a much smaller version of this county includes Miami.)
Around 2:00 am on August 7, 1840 – after Capt. Housman placed a price on the heads of Indian men, women and children – a band of over 100 Calusa Indians attacked Indian Key and massacred the residents, except a handful of survivors who fled to a tall ship moored offshore. These survivors set sail for Key West the next day. Watch out when boating near Indian Key today, because the depth of the surrounding waters is now much, much shallower. (For more details, visit www.keyshistory.org.)
In 1889, Key West was America’s richest city per capita. Over the years, the pioneers of other areas of the Keys also became quite prosperous by fishing, sponging, and raising pineapples, tomatoes, key limes, melons, tamarind and breadfruit. Prior to the Labor Day Hurricane of 1935, which razed much of the topsoil of the Upper Keys, hundreds of shiploads of pineapples were shipped to northern markets annually.
From 1905 to 1912, Henry Flagler built the Florida East Coast Railroad, “the railroad that went to sea,” linking Key West to mainland Florida for the first time ever. In fact, “Flagler’s Folly” gave Marathon, once a base camp for the railroad, its name. Record has it that, because Flagler’s advanced age caused him to fear he wouldn’t see the railway’s completion, he made a plea to railroad workers to finish in his lifetime. Two years of “marathon” work began in order to finish the entire route. On January 22, 1905, the day after completion, Flagler boarded a train for Key West with great fanfare. His goal achieved, Flagler died a few months later.
With the completion of the railway, fishing camps and farms soon sprung up on previously inaccessible islands.
On September 2, 1935, the Labor Day hurricane destroyed much of Flagler’s railroad. Beginning in 1936, the remaining bridges (such as the Seven Mile Bridge south of Marathon and the Old Bahia Honda Bridge at Mile Marker 37) were adapted for automobile traffic. Because the track area was too narrow for two lanes of cars, the roadway was built atop the structure. This new Overseas Highway was opened on January 25, 1938 – the first time it was possible to drive to Key West without boarding a ferry.
Today the Keys are also known as the Conch Republic, which was officially established on April 23, 1982. The U. S. Border Patrol established tollgates slowing traffic to and from the Keys. In response, Key West Mayor Dennis Wardlow seceded from the Union, declared war on the United States, immediately surrendered and requested $1 million in foreign aid – as the Conch Republic Air Force (which of course consisted of pelicans, yes, those adorable birds) guarded Conch Republic airspace.