frank-valentineAs captivating as the time-worn ruins of Europe, scores of centuries-old buildings and other structures made of a unique oyster shell concrete called tabby mark a meandering trail along the southeastern coast from Charleston, S.C., to St. Augustine, Fla. They are survivors, often the sole survivors, of some of the earliest European settlements in what is today the United States.

The old tabbies provide fascinating vignettes of the area’s history and tangible reminders of some of the people involved in the nation’s turbulent founding and growth.

The oldest masonry fort in the continental United States was built in the late 1600s of coquina stone and tabby in St. Augustine, the country’s oldest city. Among the fort’s builders were slaves who escaped from British colonies and fled south to Spanish Florida, traveling by way of the nation’s first underground railroad which predated the more famous escape route to the north by more a century. The escaped slaves later formed the first sanctioned settlement of free Africans in North America.

The first known British-built tabby appeared in Charleston in the form of a brick-faced tabby powder magazine constructed as early as 1703.

Georgia’s founder, General James Oglethorpe, built Fort Frederica on St. Simons Island in 1736 to guard against Spanish incursions from Florida. The fort’s major buildings and many homes in the fortified town were made of tabby.

Tabby is the first concrete ever used in North America. Spanish, free Africans and slaves, French, Native Americans, Danish and British colonists all employed it to build some of the earliest and most significant structures in the fledgling nation. Decisive battles that shaped the country’s future were fought in tabby forts. Colonists lived in tabby houses and worshiped in tabby churches and chapels of ease. After the civil war, former slaves built their own churches of tabby.

Coastal planters whose wealth made them the mainstay of the colonial economy used tabby to build rice and sugar mills, corn and cotton barns. African slaves whose labor made the plantations so profitable built and lived in tabby cabins. Some of the more enlightened planters built tabby hospitals for their slaves.

Tabby breweries and distilleries provided courage and comfort in perilous times.

chocolate-ga-dnrEuropean colonists liked the reassuring Old World look of permanence and strength that tabby gave their New World buildings.

They walked on polished tabby floors, kept out the elements with strong tabby roofs, raised their homes high off the mosquito-ridden coastal lowlands with tabby foundations, and cooked and heated with fireplaces whose chimneys were built of tabby bricks. Thick tabby walls made their homes and work buildings cooler in summer; warmer in winter. Tabby’s strength and maleability made it ideal for a variety of structures: indigo vats, yard and garden walls, crypts, docks and seawalls.

In the late 1800s, Standard Oil millionaire Henry Flagler erected lavish tabby hotels in St. Augustine that set Florida on a path toward resort development and tourism that continues today. The tabby Ponce de León Hotel, the first large structure of poured concrete in the nation, hosted presidents, celebrities and some of the wealthiest people in the world. The old hotel is now home to Flagler College.

Behind each historic tabby is a story. Some tell of battles that shaped the country’s future. Others feature well-known historic figures who admired tabby, experimented with it, used it in imaginative ways and praised its virtues to others. Many of the stories that play out along the Tabby Trail are simply tales of everyday life in colonial, antebellum and later days as seen through the eyes of people whose lives were touched, in one way or another, by tabby.

One unusual modern story involves a retired Savannah police officer who spent almost a decade in the 1980s and 1990s excavating, by hand, the extensive foundation of the antebellum tabby rice mill he discovered beneath his modest home in Darien. Because he values his privacy and worries that his beloved pack of adopted stray dogs might intimidate visitors, he does not open the ruins to public viewing. But the saga of his tabby discovery and his personal big dig makes fascinating reading.


When the Spanish founded St. Augustine in 1565, they erected a wooden fort to protect their small colony from enemies. They rebuilt that fort eight times over the next century as each one was destroyed by fires, rot, hurricanes or hostile forces.

The Spanish crown finally approved the funds to build a masonry fort in the late 1600s. The magnificent Castillo de San Marcos was constructed of coquina, a semi-rare sedimentary shellstone found in a few places in coastal Florida, and oyster shell tabby, which was made on site. St. Augustine’s fort was ceded to other countries over the years but never again fell to man or natural forces. It stands today as it has for more than 300 years.

When Spanish colonists crossed the Atlantic, they brought with them the knowledge of how to make lime by burning limestone, bones or shells at high temperatures.

This type of lime, when mixed with water, sand and aggregate such as gravel or pebbles, undergoes a chemical change that makes the mixture harden around the aggregate into durable concrete.

There was no ready source of limestone or bones in coastal Florida. There were, however, mountains of ancient oyster shells that could be burned to make lime and to use, crushed or whole, for aggregate.

frank-valentine1Tabby got a foothold in the New World because it was an ideal building material for its time and place.

In colonial days, good bricks were rare and expensive and, unless the construction project was next to a brick kiln, the heavy material required transport.

Portland cement was discovered in England in 1824 and first manufactured in the United States in 1871, long after tabby had made its mark on the southeastern coast.

Coquina occurs in only a few places in coastal Florida and must be quarried and dried, sometimes for years, before it can be used.

Tabby’s ingredients were free and available near every coastal construction site. Early builders learned to make their tabby with fresh water and salt-free sand after discovering that salt made the oyster shell concrete crumble.

Oyster shells, tabby’s signature ingredient, were everywhere. Dead shells washed up in great drifts on beaches and mudbanks. Builders in a hurry sometimes threw live oysters into the tabby mix, as they did at Fort Frederica. There is no record of how the soldiers and settlers in the fortified town reacted when the oysters spoiled.

The bulk of the shells early builders used for tabby were laid down over thousands of years by aboriginal inhabitants of the coast who piled them beside the tide waters where they harvested and ate the shellfish, their diet staple.

Some of the mounds and rings, called middens, were huge. The largest of three shell rings on Sapelo Island, Georgia, measures 300 feet in diameter and rises in places a dozen feet above the forest floor, even though it has settled over the centuries and lost tons of its bulk to tabby and to old Sapelo roads paved with loose shell. There is an even bigger shell ring, surrounded by smaller rings, on Fort George Island, Florida. The large ring is more than 800 feet in diameter.

The Irene shell mound at the junction of Pipemaker’s Creek and the Savannah River was so prominent it served as a landmark for Indians and early British settlers.

Eighteenth century naturalist William Bartram described a series of middens on the Georgia-South Carolina border that rose “seventy feet higher than the surface of the [Savannah] river” and were composed, to a depth of  30 or 40 feet, of fossilized oyster shells, “internally of the color and consistency of clear white marble.” The individual shells were 15 to 20 inches long, six to eight inches wide and their hollows were “sufficient to receive an ordinary man’s foot,” Bartram wrote, adding, “The adjacent inhabitants burn them to make lime for building, for which purpose they serve
very well . . .”

More than two centuries after contact, Native Americans were still wary of disturbing the larger middens. When German Protestant missionaries from Moravia built a school for Indians on the Irene mound in 1736, the school’s headmaster, the Rev. M. Benjamin Ingham, wrote to a friend, reporting that Indians who watched the school’s construction asked if the British weren’t afraid of “building on the hill” because “fairies haunted hills.”

While the larger shell mounds and rings were used for burials and other ceremonial purposes, the smaller middens were probably just trash dumps. Early builders mined them all for shells to make tabby.

To make the lime, they dug firepits, filled them with wood, then layered wood and oyster shells until the structure, called a lime rick, was five or six feet tall and crowned with a dome of shells. Some of the ricks were as big as boxcars, according to historic records. As the rick burned, it reached temperatures of over 800 degrees centigrade and left an inseparable residue of lime powder and wood ash. Chemical tests done during the 1990s by Dr. Lauren Sickels-Taves, an architect who specializes in tabby and other historic masonry, indicate the ash was an important chemical component of tabby concrete.

The fact that old tabby often contains shards of prehistoric pottery, arrowheads, spear points, bone fish hooks and other artifacts is further proof that so much of the shell came from the ancient middens. There is an arresting relic in the tabby wall of a slave cabin on state-owned Ossabaw Island, Georgia, that may have been fairly new when the wall was built: the jawbone of an animal, complete with teeth.

Building with tabby was labor-intensive. To make a wall, builders first constructed a wooden mold or cradle, 12 to 18 inches high, the width and length of the wall and open top and bottom. Round spreader pins held the side boards in place. The holes left by the spreader pins were were later covered with stucco or plugged with tabby.

Builders poured the wet tabby concrete into the cradle and when it hardened in a few days, they removed the spreader pins, raised the cradle and set it on top of the dry tabby to pour the second course. They continued moving the cradle higher and pouring tabby until the wall was done.

Pour lines and spreader pin holes are distinctive features of weathered tabby walls.

Tabby floors were poured in place. Linseed oil was pounded into the semi-dry mortar until the floor had the sheen and feel of polished marble. When a tabby floor became rough and pitted after a decade or so of use, the occupants poured a new floor on top of the old one. The oldest house in the United States has four layers of tabby floors.

Flat tabby roofs were poured over a framework of beams interwoven with a lattice of boards, sticks and plant fibers. The roof was finished with sand and tar to make it waterproof.

First-time visitors to the southeastern coast are usually fascinated by tabby’s history and rugged beauty.  Many are surprised that the oyster shell concrete has been around for centuries but is not nearly as well-known as adobe, the characteristic building material of the American southwest.

Nobody knows how many historic tabbies have been lost to weathering, vandalism or bulldozers over the centuries. Others are simply lost, camouflaged by bushes and brambles, hidden in palmetto thickets, covered by tangles of wild grape vines and Cherokee roses. Hunters and hikers stumble across them in the woods, eroded beyond recognition, reminiscent of mythical forest giants.

Historic tabbies still turn up from time to time.

Archaeologists and historians who studied old maps and documents to locate a colonial South Carolina plantation found a lost tabby prize in the 1990s: a rare tabby indigo vat. Such vats were used to make the precious blue dye employed extensively in early America and Europe before chemical dyes were available. The vat’s four chambers are in remarkably good shape, even though small trees are growing in the rich organic debris built up in the tanks over centuries.

Indigo was one of the nation’s first important money crops. It was used to dye the bunting background of America’s first star spangled banners; it colored Mississippi’s famous “Bonnie Blue Flag” of secession. American patriots wore uniforms dyed with indigo during the Revolutionary War. The Tabby Trail introduces readers to the story of the 16-year-old girl who grew and processed the first indigo in British North America on a Wappoo Creek plantation near Charleston.

People today still build with tabby, although real tabby construction is expensive, primarily because of labor costs.  While early builders skimmed rough tabby walls with a topcoat of smooth stucco to protect them from the elements and make them look more refined, modern builders usually skip the stucco. People today like the look of natural tabby, old or new, in part because it is such a perfect fit for its coastal environment.

In the same way adobe mimics the warm red-browns of the desert southwest, tabby echos the subtle grays of Spanish moss and foggy mornings. The oyster shells in the concrete matrix give tabby a soft luminance, like the sheen of sand dunes not long after dawn. Sometimes small pearls glow against the shells’ satiny inner lining; reminders of the nation’s first settlers on the southeastern coast, the Native Americans who adorned themselves with pearls and gave them as gestures of friendship to early Europeans.

With the exception of a few off-trail tabbies on Florida’s west coast and a scattering in other coastal states, the vast majority of historic tabbies are located along the Tabby Trail, usually in beautiful settings within an oyster shell’s throw of salt water, and are under the protection of local, state and federal governments, private foundations, and religious and historic organizations.

A few significant tabbies, including the 18th century tabby home of Declaration of Independence signer Button Gwinnett on St. Catherines Island, Georgia, are on private land, off-limits to all but invited guests.

Most of the old tabbies are open to the public along the Tabby Trail between St. Augustine and Charleston, a stretch of just under 400 miles.

Editor’s note: This article is an excerpt from “The Tabby Trail: A Guide to Historic Tabby Buildings of the Southeastern Coast,” a book in progress by Jingle Davis, a former writer and editor for The Atlanta Journal-Constitution. Davis, who now lives in Athens with her husband Frank Swisher and Glenda the dog, is a native of St. Simons Island in the heart of tabby country.

Top photo by Frank Valentine: Three tabbly slave quarters, thought to be the most complete remaining on the Georgia coast, are the oldest surviving structures of the North End plantation complex at Ossabaw Island.

Middle photo: Tabby at Sapelo Island, Ga., by Georgia Deparatment of Natural Resources.

Bottom photo by Frank Valentine: A white tail deer jaw bone was mixed in with oyster shells by slaves when they built this tabby slave quarters at Middle Place on Ossabaw Island, Ga.

Jingle Davis

Jingle Davis

Jingle Davis, who lives in Athens, Georgia, has been a journalist for 25 years, freelancing for The New York Times, Sports Illustrated and other national and regional newspapers and magazines. She operated the coastal bureau of The Atlanta Journal and Constitution for about a decade before moving to Atlanta to work as a metro reporter. She became a metro editor in 2003, first editing three weekly zoned editions of the paper (City Life Buckhead, City Life Midtown and South Metro), then moving to metro editing. She served as assistant city editor and was acting city editor before taking a buyout retirement offer from the paper in June, 2007.