Earlier this year, however, the National Park Service agreed to swap most of its property at that corner for 78 acres within Valley Forge National Historical Park owned by the private American Revolution Center, which is seeking to establish a museum. That deal is expected to close within weeks.
The lab incorporates a large, active corps of volunteers to analyze and research the trove of artifacts uncovered in 2000 and 2001, prior to construction of the National Constitution Center on the northernmost block of Independence Mall.
The Constitution Center excavation, which uncovered more than a million artifacts ranging from Native American relics to pumps from the city's first water system, is widely viewed by historical archaeologists as one of the greatest urban digs in American history.
Park officials in the past have cited the lab's use of volunteers as an essential part of the massive project.
The archaeology lab had been expected to move directly across Third Street into the now-closed First Bank of the United States building. All artifacts were packed and ready to move earlier this summer when park officials determined that the First Bank's electrical and mechanical systems needed a complete upgrade, which could take up to two years.
As a result, the lab work will proceed in a small building at 325 Walnut St. and will be closed to the public except by appointment. The space is so small that the volunteer program will be severely restricted, officials said recently.
"It's a reminder to us to get the lab up and running sooner rather than later," said park spokeswoman Jane Cowley. "It is a major volunteer program, and we will redouble our efforts."
With the addition of nine volunteer programs designated this year, the Preserve America Steward program has named 30 exemplary volunteer efforts over the last several years.
The Independence Living History Center was the only program honored in Pennsylvania and New Jersey in 2010. One other Pennsylvania program was honored in the past, the Pennsylvania German Cultural Heritage Center at Kutztown University.
"Historic preservation has always relied upon motivated, active volunteers," said Donaldson of the federal advisory council.
Contact culture writer Stephan Salisbury at 215-854-5594 or firstname.lastname@example.org