In 1895, Frank Hamilton Cushing, a pioneering anthropologist from the Smithsonian Institution, turned his attention to an obscure area of swampland in southwestern Florida. He had been shown a collection of objects that had recently been found by workers extracting peat from a bog on Key Marco, on Florida’s Gulf Coast northwest of the Everglades. Cushing was one of the country’s preeminent scholars of Native American culture, yet the artifacts he saw perplexed him. The finely crafted relics, which he estimated to be quite old, were unlike anything he had seen before. Cushing decided to make the long, arduous trek to Key Marco, where he organized a team to further investigate the site.
Over the next two years, Cushing’s team retrieved thousands of objects that stunned the archaeological community. Preserved in the muddy, oxygen-free conditions of the bog were tools, weapons, ceramics, and household objects made from bone, shell, wood, and woven fibers. There were also painted ceremonial masks and carved animal heads. A six-inch wooden statuette of a feline, known as the Key Marco Cat, is considered by many to be one of the finest pieces of pre-Columbian Native American sculpture.
The people who crafted these objects were a mystery to Cushing and other scholars. Their material culture was seemingly older than and unrelated to that of Native groups living in Florida at the time, such as the Seminole or the Miccosukee. The men and women who had created and used these items had inhabited Florida’s shores long ago. They had, however, left behind evidence of their lives, especially of their mastery of their marine environment. Buried in the muck of Key Marco were fishing nets woven from palm fibers, hammers and other tools made from conch shells, and blades fashioned from shark teeth. Even the land on which they lived owed itself to the sea, as it was formed from heaps of oyster, clam, and conch shells.
Cushing named these people the Key Dwellers, but archaeologists now know them as the Calusa, which Spanish sources say meant “fierce people” in their language. Researchers have learned that the Calusa, whose empire and influence spread across a territory from Charlotte Harbor on the Gulf Coast across to the Atlantic Ocean and down to the Florida Keys, were the dominant Native group in southern Florida when Europeans arrived in the sixteenth century. Unlike other complex societies of the Americas, such as the Inca, Aztecs, and Maya, the Calusa eschewed large-scale agriculture, instead building their empire on marine resources. For more than 200 years, they resisted Spanish colonization and Christianization until, ultimately, they disappeared from Florida’s shores.
For most of the century after Cushing’s discoveries, much remained unknown about this enigmatic people, as only sporadic archaeological work took place. What scholars did learn came largely from texts and maps written and drawn by the Spanish, who first encountered the Calusa in the 1500s. However, in the 1980s, archaeologist William Marquardt began intensively investigating Calusa sites in south Florida for the first time. “When I first visited a Calusa archaeological site, it was an exotic and compelling experience,” says Marquardt, who is curator emeritus at the Florida Museum of Natural History. “Little systematic archaeology had been done in the area and it was one of the least understood parts of Florida.” For the past four decades, Marquardt has led archaeological projects that have helped pull back the curtain on the Calusa and create a new understanding of how they achieved a level of political complexity nearly unparalleled among hunter-gatherer societies in the Americas.
The Calusa themselves did not leave behind any written history. The earliest mention researchers have of their existence comes from sixteenth-century Spanish accounts, especially those of Hernando de Escalante Fontaneda. Escalante Fontaneda was shipwrecked off the Florida coast as a teenager and taken captive by the Calusa, living among them for the next 17 years. From his accounts, it is clear that the Calusa were the most powerful Native group the Spaniards encountered in Florida. Over the course of two centuries, the two nations were by turns enemies and allies. “I would characterize the relationship as mutually beneficial at times,” says Marquardt, “but mostly acrimonious and tense.”
From the start, the Calusa made it plain to the Spaniards that they would not easily gain a foothold in southern Florida. Juan Ponce de León is famous for his fabled 1513 voyage to Florida in search of the fountain of youth. His second journey, eight years later, is much less well-known. It was during this mission, aimed at founding the first Spanish colony in what is now the continental United States, that de León’s settlers landed in Calusa territory. By 1521, the Spanish had been present in the Caribbean for more than two decades and their reputation preceded them. “The Calusa were aware that the Spaniards were intent on conquest and slavery years before Ponce de León arrived on their shores,” says Marquardt. “They chose to resist and did so successfully.” The Europeans soon experienced the Calusa’s resolve in a face-to-face confrontation that left de León mortally wounded. The Spaniards turned around and left. Plans for a Spanish colony in south Florida were thwarted, at least temporarily.
Some 40 years later, the Spaniards returned, ushering in their first sustained period of contact with the Calusa. In 1566, Pedro Menéndez de Avilés, the first Spanish governor of Florida, arrived at the Calusa capital to hammer out an alliance with their leader, King Caalus. The Calusa needed support from the Spaniards to help ward off threats from their northern rivals, the Tocobaga. The Spanish needed a base in southern Florida from which to expand their burgeoning New World empire. Escalante Fontaneda, who acted as translator, and another Spaniard, named Gonzalo Solís de Merás, later described the meeting, the Calusa settlement, its buildings, and how Menéndez’s retinue of 500 men was met by a crowd of 4,000 Calusa. Caalus is said to have entertained the Spanish governor in a house large enough to hold 2,000 people, where extravagant ceremonies were held as the terms of the treaty were hashed out. This agreement was sealed by the marriage of Caalus’ sister to Menéndez. Until recently, the precise location of this meeting, and of the Calusa capital itself, were unsubstantiated.
One of the main goals of Marquardt’s research, which is codirected by University of Georgia archaeologist Victor Thompson, has been to finally confirm the location of the Calusa capital and especially the so-called House of Caalus. “We have the descriptions,” Thompson says, “so we aimed to identify the architecture and corroborate it with the historical documents.” Their focus was a small island in the middle of Estero Bay known as Mound Key, which scholars had speculated for decades might be the site of the Calusa capital. Although it appears today to be indistinguishable from any other island in subtropical coastal Florida, blanketed by lush green vegetation and mangrove forests, the dense foliage obscures Mound Key’s secret—the entire island was constructed by human hands, built up with hundreds of millions of seashells, fish bones, and other materials. Prior to Marquardt and Thompson’s work, little was known about the island’s topography or how or when it was constructed. Their team recently used lidar, ground-penetrating radar, coring, excavation, and radiocarbon dating to gain a clearer understanding of how Mound Key was created and what it might have looked like in the past.
Beginning around A.D. 500, the Calusa began a 1,000-year process of meticulously constructing and shaping the island by collecting, consuming, and discarding massive quantities of mollusks. The island covers 125 acres and reaches a height of 30 feet at its apex. Creating it was an extraordinary feat. Mound Key’s volume of 21 million cubic feet is about one-quarter that of Egypt’s Great Pyramid of Giza, but, as Thompson points out, there is one key difference between the two. “Nobody ate the Great Pyramid of Giza before they built it,” he says. “That’s exactly what you have at Mound Key. All of this is food waste. It is, in essence, a consumed landscape and then a constructed landscape.”
Building the island was a complex process that required a cooperative and organized labor force. Over hundreds of years, the heaps of shells and their sediments were sculpted and molded into a series of terraces and two prominent peaks, measuring 18 and 30 feet high. Rising above the flat Estero Bay landscape, the island’s mounds would have been a marvel to behold at the time. Although Mound Key is overrun with vegetation today, it would have presented a much different profile 500 years ago. “It would have been gleaming white with geometric works in the middle of the bay,” says Thompson. “It certainly would have made a statement.”
Lidar imaging of Mound Key has revealed that a waterway, known as the Grand Canal, measuring 1,200 feet long and 90 feet wide, was dug through the island, dividing it in half. Several smaller tributary canals branched off, leading to the island’s interior and creating a network of channels perfectly suited for Calusa canoes. At the site of Pineland, the second largest Calusa settlement, 20 miles northwest of Mound Key, the central canal was two and half miles long. Its construction required the removal of more than a million cubic feet of earth. “The Calusa knew the water and were expert hydro-engineers,” says Thompson. “South Florida had a highway system of waterways, be it ones that were natural or human constructed.”
Mound Key’s geography, topography, and landscape seemed to Marquardt and Thompson to match the sixteenth-century Spanish maps and records that described the Calusa capital, but definitive archaeological proof remained elusive. Their team needed something conclusive, such as evidence of the famed House of Caalus, which they began searching for in 2013. They believed the most plausible location was atop Mound 1, the island’s highest point. However, the 7,000-square-foot mound was covered in thick vegetation, making extensive archaeological work impossible. The only accessible area was a previously exposed strip of land along the summit’s edge, but this offered an extremely limited view of the mound. “We thought if the house was as big as the sources say it was, it must have taken up the entire summit,” says Thompson, “so the walls have to be close to the edge.” And indeed, they were.
After ground-penetrating radar detected anomalies in the soil, the team began digging and exposed postholes and remnants of an oval building estimated to be around 80 feet long and 65 feet wide, making it one of the largest Native American structures discovered in the Southeast. Radiocarbon dating indicated that the house was first built around A.D. 1000 and was rebuilt and renovated during several phases over the next 500 years. Thompson believes that a structure that large and in such a prominent location must have been the building that the first Spanish visitors describe as being associated with the hereditary Calusa kings. “Our interpretation is that there was a kind of powerful, long-lived lineage associated with the top of that mound,” he says.
The footprint of such a structure, built atop the highest point on an impressive, constructed island in southwest Florida, which also fit sixteenth-century descriptions, might be convincing evidence that Mound Key was the capital of the Calusa Empire, but Marquardt and Thompson wanted additional proof. This soon came from Mound 2, the island’s second-highest point. After the meeting between Caalus and Menéndez in 1566, historical records indicate that the Calusa allowed the Spanish to construct a fort and a Jesuit mission, known as San Antón de Carlos, within their capital. The whereabouts of this fort, which was known to have existed somewhere along Florida’s southwest coast, had been lost for more than 400 years. Over the past decade, though, archaeological investigation led by Marquardt and Thompson atop Mound 2 has revealed remains of Spanish-style buildings, sixteenth-century Spanish artifacts, and a section of stout defensive wall. These could only have belonged to the fort and settlement established by Menéndez in 1566. There was no longer any doubt—Mound Key was the home of Caalus and the Calusa capital.
On the eve of the Spaniards’ arrival in America, there may have been 50 to 60 Calusa communities in central and southern Florida with a total population as high as 20,000. During his travels, the Smithsonian’s Cushing estimated that there were several dozen shell mounds lining the coast of southwest Florida. Some of these, such as at Pineland, Josslyn Island, Key Marco, and Mound House have proven to be rich sources of Calusa artifacts. The kingdom was unquestionably ruled by a leader based in Mound Key, whose power, wealth, and prestige were enhanced through tribute paid to him by client communities across Florida. These gifts, which signified allegiance and loyalty to the king, included food, animal hides, mats, and feathers. Paradoxically, the Calusa king’s control over his vast territory was initially strengthened by the arrival of the Spanish in the New World. By the dawn of the sixteenth century, although the Spanish themselves had not yet landed on the peninsula, European goods and gold were already being funneled into Mound Key, sent there by subordinate Native groups along Florida’s southern shores who poached cargo from frequent Spanish shipwrecks. Access to and control of these highly prized European goods further reinforced the Calusa king’s authority.
Archaeologists often refer to this type of society as a complex polity, in which power is wielded by a select number of individuals and families. These elites or nobles have privileges that are denied to others, while the principal leader is responsible for amassing resources, especially food, and redistributing them throughout the community. “Almost all such societies are agricultural,” says Marquardt. Most cultures of this type in the New World relied on surplus production of maize to maintain a stable society. To the surprise of most researchers, the Calusa became the dominant regional power player without large-scale cultivation of maize or any other crop. “They were fishers, not farmers,” Marquardt says, “and the only fishing society to have become a tribute-based kingdom.”
The Calusa simply didn’t need agriculture because they lived in one of the world’s most fertile estuarine environments, which provided access to a practically unlimited abundance of plants, wildlife, fish, and shellfish. Nearly all the Calusa’s dietary needs could be satisfied by the sea. “If you think about agriculture in terms of a surplus product, it’s reliable, it’s predicable, and it’s abundant,” says Thompson. “What are estuarine resources other than reliable, predicable, and abundant?”
Be that as it may, it might still have been difficult at certain times of the year to consistently feed Mound Key’s population, which may have totaled around 2,000 in the sixteenth century. In a maize-growing society, surplus agricultural products can be harvested, stored, and redistributed throughout the year. This was not easy for the Calusa to do since fish does not last long in the heat without spoiling. In 2017, Marquardt and Thompson began uncovering another of the Calusa’s secrets and another example of their advanced hydro-engineering skills: watercourts that functioned as giant fish tanks.
Once again using lidar, geophysical survey, coring, and excavation, the team identified two immense rectangular features hidden beneath Mound Key’s surface that had once flanked the Grand Canal near its southern end. The enclosures were created 600 to 700 years ago by heaping up piles of shell and sediment to create a berm about three feet high. Both had gates that faced the canal and allowed the interior central space to be inundated with seawater. The Calusa would have been able to place nets across the canal and direct schools of fish, particularly mullet, into the adjacent watercourts through the openings, which could then be closed, trapping the fish inside. Together, the combined storage area of the two watercourts totaled around 1.5 acres, enabling an essential food source to be stored and kept fresh and readily at hand.
There is also evidence that wooden racks once stood near the watercourts, where fish could be processed, dried, and smoked. The researchers determined that the island itself had been carefully graded to create gentle slopes from the watercourts to the tops of Mounds 1 and 2, which allowed for easier transportation of resources. The Calusa had engineered an almost perfect system to maintain and exploit their food resources without the need for large-scale agriculture.
During the era of European colonization, the Calusa proved themselves worthy adversaries to their would-be Spanish conquerors, safeguarding their independence longer than any other Indigenous Floridians. “The Calusa maintained their society and their cultural traditions for nearly 200 years following European contact, far longer than many other societies in the eastern United States,” says Marquardt. They endured despite the rapid collapse of the treaty forged between Menéndez and Caalus on Mound Key. The king became enraged that the Spanish were not upholding their end of the deal to aid him in his conflict against the Tocobaga and began plotting against his European guests. Caalus was betrayed and assassinated in 1567. His cousin and successor, Felipe, who conspired in Caalus’ downfall, initially maintained an alliance with the Spanish, but also eventually turned against them and attacked a Spanish supply ship. He, too, was executed, in 1569. The Calusa burned their settlement at Mound Key and abandoned the island. They returned soon thereafter and remained politically dominant in southern Florida for another 100 years, but the Spanish had had enough. The Jesuit mission and fort at San Antón de Carlos were abandoned.
In the end, it would not be the Spanish but the English and their Native allies who caused the Calusa people’s demise. In the early eighteenth century, in what would become one of the largest slaving raids on North American soil, marauding groups of Yamasee and Uchise Creek from the north invaded southern Florida on lucrative missions to enslave the Calusa and sell them to the English, who were based in Georgia and the Carolinas. The attackers were armed with European weapons; the Calusa were not. In just one generation, the Calusa people were all but wiped out and the remaining few moved farther and farther south until only a small number survived in an enclave in the Florida Keys. The Spanish attempted to come to their aid and began transporting the surviving Calusa from Florida to Cuba, but most of them died of disease. By the 1760s, no Calusa remained in Florida and no descendant communities survive. Their once-great empire seemed to be forgotten, so much so that when Cushing came across the trove of Calusa artifacts from Key Marco, neither he nor any other archaeologist of his day knew who was responsible for them. The story of this unique, politically complex, and highly advanced culture is finally coming to light. “I think credit hasn’t been given to the Calusa,” says Thompson. “It’s long overdue. They deserve their time in the spotlight.”
Jason Urbanus is a contributing editor at ARCHAEOLOGY.
