Federal Detention Center and National Constitution Center Sites
The first two sites found were part of the Federal Detention Center and National Constitution Center Sites. Located far from the Delaware River, in one of the highest elevated parts of the city, these sites sat along two small interior streams that existed during the 18th century.
Metropolitan Detention Center Site
(36 Ph 91) — 7th and Arch Streets
This site was excavated in 1995-96 and uncovered the remains of houses that were built here in the late 18th-early 19th centuries, as well as a section of the original backyard space behind these buildings. In that back yard, archaeologists found a small Native campsite and some stone tools — a triangular projectile point ("arrowhead"), cutting and chopping tools, and fire-cracked rock from a hearth or campfire. It is believed that this site dates to sometime between 1000 and 1600 A.D. Click for a report of this project and its findings.
National Constitution Center Site
This site encompasses the entire northernmost block of Independence Mall, and was excavated between 2000 and 2003. At its height, this investigation involved a crew of nearly 60 professional archaeologists.
The National Constitution Center Site
About two-thirds of this block was excavated prior to the construction of the National Constitution Center. Approximately 115 of the house lots that once existed on this block during the 18th and 19th centuries were uncovered and intensively studied, as was a portion of the former Second Presbyterian Church Cemetery (ca. 1752-1864).
At the city's founding, this area was a large gently rolling upland meadow. In the late 18th and early 19th centuries, this part of the city became a crowded working class residential neighborhood. In the late 19th and 20 centuries however, it was extensively re-developed and transformed into an integral part of the city's commercial core. In the late 1950's, all the buildings on this block were torn down to make way for the creation of Independence Mall.
Despite this long period of occupation, development, and repeated transformation, when the site was excavated archaeologists discovered that sections of the block's interior still contained extensive preserved patches of the original landscape and ground surface (shaded dark blue). This original ground was found in areas that were once open back yards, under the beds of interior streets and alleys, and beneath buildings constructed with no, or only shallow basements.
These intact sections of the site were preserved mostly in the central portions of the block, in an area that was once slightly lower-lying than surrounding ground. Soil experts believe this lower ground was once an upland wetland, and might have contained a small seasonal stream that fed into nearby Minnow's Run. Over time, this lower ground was gradually filled in by local residents, thereby helping to cap, seal, and preserve the original ground surface. This image shows those undisturbed former back yard areas being excavated.
When these undisturbed portions of the original ground surface were carefully excavated, archaeologists recovered a number of artifacts made and used by Native Americans — evidence of a small, short-term campsite probably created in order to exploit the unique plant or animal resources of this upland environment. For the most part, recovered artifacts included a handful of stone tools and the debris, or "flakes", created during the manufacture of those implements.
Two of the tools found within this encampment — a quartz projectile point and a piece of hand-drilled rock, possibly part of an unfinished "gorget"(a decorative piece worn around the neck like an amulet or breast plate). Based on the style of this point and some of the other artifacts found, archaeologists believe the campsite was made and occupied sometime around 1,800–1,000 B.C.
In addition to these stone artifacts, archaeologists also recovered a number of more recent artifacts that may also have been used or made by Native Americans — glass trade beads, so-called "gaming pieces"made from pieces of ceramic plates, pierced coins, cowrie shells, and "knapped"or modified glass and ceramic pieces. Though it is not yet certain, because artifacts from this site are still being studied, the artifacts shown here may indicate that Native Americans revisited this site during the early Colonial Period of the city's history.