The fragment of old cow bone contained a secret.
Found downtown among the historic homes of Charleston, it held coded information about how people lived three centuries ago.
Four small pieces of parrot bone excavated in the 1970s revealed something important about Charleston in 1820.
And those bits of charred sweetgrass baskets discovered around the same time? They contained vital information about the history of slaves in the Southeast.
But who could break the code? Who could unencrypt the message?
Martha Zierden, curator of historical archaeology at the Charleston Museum, has been digging in the city since 1981. Her first dig was at the Heyward-Washington House, a plum job for an up-and-coming urban archaeologist.
The timing was just right. City officials, determined to improve the city’s landscape, needed partners associated with historic preservation, and historians needed willing city officials to help provide opportunities for exploration.
Both depended on Zierden and her diggers.
Another bit of serendipity: In 1984, John Brumgardt became director of the Charleston Museum and quickly shifted its focus to regional natural and social history, creating a department of archaeology.
So Zierden’s investigations became more deliberate as excavations produced bone fragments, pieces of earthenware, an array of household items and much more, opening a window onto the past. And it wasn't only the artifacts of stately mansions and wealthy gentry that received her attention.
“We became a little more formal with investigations into underrepresented people,” said Zierden, who was awarded the 2018 Albert Simons Medal of Excellence in February by the College of Charleston.
Enslaved people left little written record of their lives, but the objects found by archaeologists yielded terrific information about their diet and activities, and the environment in which they lived and worked.
The goal of this kind of scientific inquiry, Zierden said, is “to fill out the details of daily life.”
And archaeology is a critical tool that, together with oral and documented history, photographic research and scientific analysis, helps to construct a clear picture of the past.
That cow bone revealed details about animal husbandry during Colonial times, including what people ate. The bird bones, which belonged to a blue-fronted Amazon parrot, indicated that Charleston was on a global trade circuit, and also part of a pirate-infested black market. The charred basket bits provided a missing link, offering material confirmation that the basket weaving of the Lowcountry has its origins in western Africa, and that the technique has changed little over the centuries.
Zierden did not come from a family of means. She mostly grew up in Panama City, Fla., but spent a couple of middle school years in Myrtle Beach when her father, Eugene Zierden, was stationed at the Air Force base there.
Many weekends were spent in Charleston, where she and her parents visited the Charleston Museum, then located on Calhoun Street, Fort Sumter and various historic sites. Her mother, Anne Holbrook Zierden, instilled in Martha a deep interest in history. Her father, who once spent some time in Turkey, encouraged her to explore the world.
Back in Florida, Martha Zierden attended community college, then Florida State University, where she studied archaeology.
“I was interested in marine biology growing up on the Gulf Coast of Florida, but chemistry and I were not friends,” she said.
Her parents’ influence had rubbed off. Exploring history is what she decided to do. She found work in St. Augustine (“a fun and magical place”), then through a friend heard about Linda Hart, who worked part-time at the Charleston Museum and soon introduced Zierden to excavator Elaine Harold.
Zierden jumped at the chance to work with Harold on the Heyward-Washington House dig. In 1981, she was hired by the museum. A few months later, Harold and her husband moved away, leaving Zierden in charge just as the city was ramping up its urban renewal projects. The preservation community had a lot to do.
For nearly 40 years, Zierden has spearheaded dozens of projects large and small, adding critical pieces of information to the historical narrative, authoring books, mounting exhibitions and collaborating with city officials, preservationists, colleagues in academia and others. As the medal signifies, her work has not gone unappreciated.
One of the first things Katherine Saunders Pemberton did upon arriving in Charleston in 1992 was to follow the advice of colleagues and call Zierden.
“She was so encouraging, she had some leads and suggestions for me,” said Pemberton, manager of research and education at Historic Charleston Foundation. “That was a really big deal for somebody new to an area who didn’t know anybody.”
Zierden’s research has set the stage for the foundation’s push to get the city to adopt an archaeology ordinance, ensuring that some amount of historic excavation becomes automatic with every development project, Pemberton said, adding that Charleston is a little behind the curve. Other cities adopted such measures years ago, she noted.
Thanks to the rigorous and systematic approach Zierden and her colleagues have pursued, and the expectations they have set, it should not be difficult to adopt a reasonable policy that protects the material evidence of the past in Charleston, Pemberton said.
“Whenever we’ve been able to pull off some public archaeology, the public sees it and gets really excited about it, and they think it happens all the time and that we’re actively protecting our archaeological resources all the time,” she said. “But there is a false sense of security.”
An ordinance would apply to certain kinds of real estate development projects and become part of the permitting process, she said. Most construction projects wouldn’t be significantly impacted, but a certain amount of testing and monitoring and scanning — and occasionally digging — often would be required.
“It’s more expensive if you wait and discover something,” Zierden said. But if you know something is there before grading the land, driving in the pilings and pouring concrete, it’s easier and quicker to do the necessary archaeological work.
Pemberton imagines a system of zones organized according to their archaeological importance. So the scope of work would correspond with the potential for finding lots of interesting stuff.
The city’s interesting archaeological stuff includes many items attributable to African Americans, providing opportunities to supplement the written record left to us by privileged white men, she noted.
“Those slaves are not leaving written records, but they are leaving evidence in the ground,” Pemberton said.
And that’s one reason why Zierden’s work is so important: So that our understanding of history is informed by multiple perspectives.
“Martha is particularly good at this,” Pemberton said. “Her longevity, her contacts, her experience and knowledge of Charleston archaeology and all the players is something that we’ll probably never see again.”
The story of Charleston
Carl Borick, director of the Charleston Museum, could not agree more.
“Zierden is indispensable," he said. "She’s highly respected by the board and staff. Everyone defers to her for her knowledge. ... She’s the heart and soul of our curatorial staff.”
Borick is especially grateful for her attention to the history of slaves and the “role they played in building the city.”
Examining the materials that African Americans of yore used every day, including the food they consumed and colonoware pottery they used, tells us about their lives. And that social history, in all its complexity, is the story of Charleston, he said.
Lately Zierden has been part of the search for Revolutionary War siege lines behind the Aiken-Rhett House. Borick hypothesized their location and recent ground-penetrating radar scans revealed that he was right. The trenches were dug by the British during the siege of 1780 that resulted in the surrender of Patriot forces defending the city.
This summer, Zierden and Borick, with logistical support from the city, expect to do more scanning and expand the footprint of the siege lines.
Zierden also wants to conduct some isotope studies of cattle bones to learn about how the animals were raised and dispersed through the city’s markets.
That might not seem very exciting, but what it can reveal has the potential to fire the imagination.
“Everyone wants to know who they are and where they came from and how our society came to be what it is,” Zierden said. “We make that contribution.”