from every area of meadowcroft research. computer analysis makes it possible to draw an accurate picture of how the people who visited the rock shelter interacted with their environment. >> i take the raw data, generally using a thing which is data reduction process, it looks for things that behave together. say people during one time were eating a lot of fish, and as they happen to be down by the stream, they also picked up a lot of crabs and carried them up to the site and deposited crab claws and fish scales on the site. and then during other times, when they perhaps did not favor marine things, they would have gone to hunting deer or something like that. so there is going to be a simultaneous drop off in fish scales and crab claws. there is a correlation. things will come out of the stone material about their hunting patterns. . things will come out of the stone tool material that tell about how their stone tool making habits change. all of these things will add to an ever-growing array of information about how people be

director of the meadowcroft rock shelter. in the east face of the excavation there is an interesting profile here that has evidence of campfires. all of these reddish stains here, you would also see bits of charcoal and ash. that indicates were campfires were build. in that roughly six foot profile there are literally nows of years of campfires represented. in that fire pit, that was what i like to refer to at the sweet spot of the collapse of the new roof fall. when that collapsed it changed the dynamics in the site. so subsequent activity took place in the west, but for thousands of years that was the center of activity here at the site. there's another fire pit location here. in the center of this fire pit, right there, is a fresh water mollusk. that is a, a species that would have been found in the ohio river requiring a deeper and faster-moving water, and that is where that was uncovered in the center of of that fire pit. so roughly 4,000 years ago that mullosk was presumably eaten here and the remainder left in the fire

meadowcroft rockshelter by visiting heinz history center.org, and you can watch this and all other american history tv programs at c-span.org/history. >> the largest stone fort in the united states it's at the mouth of the chesapeake bay near virginia. up next fort monroe director robin read gives us a tour showcasing the history from the colonial era to its completion. in 1834 and its role in the seven civil war. >> welcome to the very pleasant place that we call point comfort. actually we call it all played comfort and it's been named that for a long time. it is here that over 400 years of history have occurred. in fact someone say even longer, some say even thousand or years. you're actually inside a case mate. case made is nothing more than a fault inside the fort wall xerox lean side the fault for wall. kind of unique for a museum to this day in time we will walk you through the museum and talk to you about the interesting history that occurred here. some of our stories will deal with the genie indians, they africans who first arrived here and there play during the civil war. thousands