Benefits of Archeology

Archeology uses material remains (artifacts) and soil information to understand humans, their daily lives, and past events What people physically leave behind is important because not everything is written down, and historical documents often reflect the biases of their time. In the case of the 1800s United States, when Fort Pulaski was built, this means that women, enslaved people, people from lower socioeconomic backgrounds, immigrants, and other historically marginalized people are often completely absent from the written record or are only mentioned in passing. When these groups are mentioned, their lives and experiences are filtered through the perspectives and biases of dominant groups. Archeology provides a glimpse into how people lived their lives, such as what they ate, what tools they used, what their clothing might have looked like, and how they liked to spend their free time. Archeology helps to shift people’s focus to under-studied topics. The interpreted history of Fort Pulaski has long focused on the 30-hour siege that took place in1862. However, there are so many more stories about Fort Pulaski and Cockspur Island that archeology can identify and highlight.

 

Archeologists dig one soil layer at a time and screen each layer separately to recover artifacts.

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Archeologists dig in layers and take out small amounts of dirt at a time to avoid damaging potential artifacts and to see changes in soil type or color and document them. Changes in soil can be seen clearly on the wall of the excavation unit. This is called a profile. Change in soil texture, color, or material can indicate different time periods or human caused events such as the destruction of a building. Soil layers will also show natural events such as a flood or fire. This information can help date a level and its associated artifacts and can bring better understanding to the history of the land throughout time. All the dirt removed from the excavation units is filtered through wooden screens. Sifting screens help ensure that archeologists do not miss any artifacts that could be used to understand the human use of the site.

 

Map of excavations for the Workers' Village Project

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NPS archeologists operate a ground penetrating radar machine on Cockspur Island.

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Knowing Where to Dig

While archeologists could pick a random spot in the ground and start digging, this is far from the most efficient method. Archeologists use many techniques to identify exactly where to dig. They often compare historic maps to modern maps to determine the approximate locations of historic structures and spaces such as gardens. Technology such as ground penetrating radar or magnetometers, can reveal anomalies underground. These technologies work by sending energy waves (like radar) into the earth. These waves bounce off the soil, rocks, and anything else below the surface. A machine measures differences in how the waves bounce back to detect differences in the ground that are called anomalies. By themselves, these anomalies do not necessarily indicate the presence of an archeology site. They could also be modern pipes or even tree roots. However, when used together with historic maps and the written record, archeologists can recognize the anomalies that are most likely to be historic features such as trash pits or building remains.

After archeologists pinpoint a certain area that likely contains an archeology site, they conduct shovel tests. Shovel tests are not full-size excavations. Instead, they function as ground truthing, to confirm the presence of a site. This process prevents archeologists from using their time and energy digging a large unit devoid of artifacts. It is also important to note that a negative shovel test does not necessarily mean that archeologists are digging in the wrong spot. Since shovel tests only target a small area, it is possible to miss artifact-rich areas. To combat this, archeologists generally conduct multiple shovel tests spread out in the same area.

 

An archeologist conducting a shovel test to try and find further evidence of Workers’ Village areas. This area was chosen after comparing historical maps with modern maps on a GIS map database.

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An archeologist digging a unit in the Laborers' Quarter.

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The Dirty Work Begins

Once an archeology site is identified, excavations begin. The standard archeological “hole” is a one meter by one meter “unit.” Soil is arranged in layers, similar to a layered cake, with each layer representing some change in the environment. This change could be a change in human activity and usage of the land, or a natural event like a flood, hurricane, or fire. Archeologists dig each layer at a time, making sure to record notes, photos, and maps (including GIS). Since archeology is a destructive science, these notes and observations are important to review to answer questions.

As archeologists dig, they look for material artifacts and for clues from the soil that can give an insight into how people used the area or other historical events in time. One big type of clue is called a feature. Features are dirt formations that stand out from the surrounding soil either in color or material. They can indicate where foundations, post holes, or artifact rich areas such as privies or trash dumps were located.

Two large brick hearths (a type of feature) were discovered in the Workers’ Village. These would have been used both for cooking and for warmth. The brick feature shown below is the hearth in the Mechanics’ Kitchen. A smaller one was found in the Laborers’ Quarter.

 

Mechanics' Kitchen hearth. Photograph was taken facing north.

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Archeologists measure soil layers as they map a completed archeology unit.

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As archeologists dig, they fill buckets with the dirt and then use a sifter to separate the artifacts from the dirt. When archeologists find artifacts, they carefully place them in bags, labeled with the location of where they were found for safe transport to the lab, where they are washed, cataloged, labeled, and analyzed. Archeologists continue to excavate until they hit what is called subsoil.

Left, two of our archeologists map the soil layers in a unit. This is called a profile map, which shows the wall of a unit and the stratigraphy (soil layers) of the soil. Archeologists dig using different colors and textures of soil as a guide for where a layer starts and stops. When the excavation is finished, these layers will be very clear on the wall. Archeologists use mapping and measuring tools to draw what these layers look like so that a record exists even when the unit is filled back in. Archeologists record the soil color and type of each layer. Archeologists do this for every unit, as well as photographing the walls, which can help compare units across an entire site.

 

Workers' Village excavation with soil layers in the walls.

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This photo (right) shows the stratigraphy in a wall profile of a unit in the Mechanics’ Kitchen. The stratigraphy (soil layers) of the unit is important because archeologists use it to understand how the site was used by humans and at what time a change in use happened. The oldest soils will be at the bottom of the unit with the more recent soil building on top of that. This means that artifacts in the lower layers were put into the ground earlier than those towards the top of a unit. An artifact that can be dated using manufacturing methods or other characteristics can, in turn, help date the layer of soil. Once a layer has a specific date, it is known that other artifacts in that layer were been discarded in the same time period.

Throughout the Workers’ Village site, the top layer of soil is topsoil. Under that layer, archeologists found a thick layer of dredge spoil. This soil used to be on the bottom of the Savannah River. Dredging is the process of removing sand from the river’s bottom to deepen the river. The sand (or spoil) is then dumped elsewhere, including on Cockspur Island. Most of the units then had a layer of clay with very few artifacts. The next few layers were 19^th century occupation layers, which had artifacts. In the photo above, a thick layer of mortar can be seen. This may show a time when masonry was being torn down or replaced. Artifacts found in this layer, along with historical records, help to narrow down a potential year for this change. There are fewer and fewer artifacts as the unit gets deeper, until there are very few or none. This is a natural level called subsoil, which is where archeologists will stop excavating.

 

Archeological excavation with distinct soil layers in the wall. This shows a unit where the left side was undisturbed and able to be excavated while the right side was disturbed by a prior archeological excavation and unable to provide any new information.

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Construction projects, utility work, and human interference can disturb stratigraphy by mixing soil deposits. When this happens, the archaeology site is like a book with all of the words scrambled around.

All the pieces are still there, but it no longer tells a story or makes sense. Since archeology destroys a site as it is being excavated, archeologists use different methods to capture how a site looked throughout the excavation. One method is hand drawing maps in the field and using a camera to take photos from above. Another method is using LiDAR technology to capture a three-dimensional image of the area and anything in the unit. Fort Pulaski archaeologists used LiDAR to document the brick hearth features that were discovered in the Mechanics’ Kitchen and the Laborers’ Quarter. This can be helpful for future questions and for being able to show the public what was found under their feet.

 

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3D LiDAR view of the archeological remains of the Workers' Village Mechanics' Kitchen.

 

Archeologist measures the caliber of a cartridge case.

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Analyzing the Artifacts

After archeologists have completed field work, they move to the lab. There, they clean the dirt off of the artifacts and catalog each one into a searchable database. This gives each artifact an identifiable number and allows archeologists to track how many of each type of artifact they have and defining characteristics that might prove important to understanding the site. Lab work can take more than three times as long as fieldwork.

One type of lab work that takes a particularly long time is called flotation. This is a way to find extremely tiny artifacts that may have fallen through the screen. Archeologists collect soil samples during excavation and use a technique with water that separates small material from the dirt. Light objects, such as seeds, charcoal, and wood will float to the top, while heavier objects like brick, mortar, ceramic, beads, and bone, will fall to the bottom. Archeologists use magnifying glasses to sort this material and then catalog what is found.

Once every artifact has been processed and cataloged, archeologists begin analysis and interpretation. This process involves researching individual artifacts and using the database to draw conclusions that add to the historical record. Objects like architectural materials can give information about building and destruction in the Workers’ Village and the types of materials that were being used. Artifacts such as pipes, ceramics, and buttons give insight into the financial reality of workers, what workers used in their everyday lives and how they expressed themselves through objects. Personal artifacts such as harmonicas, slate pencils, keys, etc. (all of which were found), gives archeologists a look into the lives of workers that is not documented and would otherwise be unknown.

 

Glass bottles dry in the drying rack after the archeologists washed them.

Glass fragments can be architectural (window glass), lamp glass, or bottle glass used for beverages, condiments, and medicine. The way bottles are made, the shapes, and colors, all provide clues that can be used to date specific bottles and other associated artifacts and can give clues into the lives of workers.

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Sharing the Wealth

Throughout the research process, archeologists share their results with the public. This allows people to share feedback, follow along with project updates, and lets other archeologists use the results to influence new archeological research. Findings are constantly being incorporated into interpretation at Fort Pulaski to tell new stories that have not been highlighted before. At Fort Pulaski, excavations are open to the public, and local high school students have participated in online field trips, virtually “visiting” the archeologists while they worked in the field. Archeologists have visited local elementary schools to teach about archeology, and field trips have come to the fort. Boy Scout programs have partnered with Fort Pulaski archeologists to help the scouts work towards their archeology merit badges. New material is constantly being shared with the public and Fort Pulaski archeologists and rangers are looking forward to offering new field trips, tours, public events, and more.


Next Section: Serving Up History at the Kitchen