coverage of the third debate between hillary clinton and donald trump. they live coverage from las vegas starts at 7:30 p.m. eastern the 90 minute debate starts at 9:00 p.m. eastern. stay with us following the debate for reaction. and watch the debate live or on-demand using your phone or desktop or tablet. listen to live coverage with the free c-span radio app. download it from the app store or google play. visiting illinois to learn about history. the next stop is the riverfront museum. we toured the exhibit on the ever-changing illinois river. we are in the illinois river

encounter here at the riverfront museum. this gallery talks about it from a historical perspective and also about the river as a means of transportation and a big part of the economy. the gallery begins with a historical look at how the river ago anded 15,000 years about the people who lived here in prehistoric times. it was a geological event 15,000 years ago. at the time, this was in a time of great glaciers. there was a glacier lake around what is now chicago and michigan. and that burst the dam. so most of the water would have come through the base or over-the-top. and it rushed down the illinois river valley, carving out a rock.

even people who are from why thereon't realize is a canyon like structure there. it was from the phenomenally powerful rush of glacial water coming down central illinois and carving out the canyons. the people who lived here, there are a number of different times. paleo indiansthe who lived here 12,000 years ago, and the archaic group. they were followed by the woodland indians. and the group that we are most known for here, the mississippian culture. they were here from 1000 years ago to 5000 years ago. you see a great representation here on the wall. actual falcon the is in chicago now for restoration. it is a copper headdress about this large that was unearthed

here when they were building along the river. there is a lot of speculation about what the falcon was for. but the best theory is that it was part of a headdress because of where it was found and the materials it was included in. both the woodland indians and wheressissippian culture wonderful farmers. thein order to make use of crops that you cultivate, you have to be able to store them. that is where pottery comes into the picture. madeof those groups wonderful pottery, a tradition that continues today. and you can see examples in the exhibit as well. what we are looking at here is a representation of the illinois waterway. river.steps in the from the elevation of lake michigan down to where it meets the mississippi river, there is a 160 foot drop.

in order to make it easier for large ships to travel to illinois, a series of locks were built in the 1900s. they were growing cities but they were still relatively small. in theulation of chicago early 1840's was 20,000. something would happen in illinois to change that dramatically. 1848, the michigan-illinois canal was built. and that connected the mississippi river to lake michigan. after the illinois and michigan canal was open, the size of chicago more than tripled in one decade. which is absolutely phenomenal. and at the same time, it telegraphs came and that allowed us to grow as well. there was such demand for transportation that another system had to be developed.

so an initiative was started just before the start of the 20th century. to reverse the flow of the chicago river. unprecedented. and i don't think it would have happened except for a scare. you know how the public can be scared and that move things along. there were a lot of cholera outbreaks in chicago because of sanitation problems. and the fear of another outbreak gave the project enough push to do him off the rivers. they chicago river flowing into lake michigan. the taliban river flowed into lake michigan. supply public drinking came from there. so they reverse the flow. the shippingted canal. and that connected lake michigan to the river.

waste sent all of the downriver. unfortunately, it went downriver as well. the illinois waterway wasn't really completed for another couple of decades. needed to create these dams to allow large ships to move with greater facility up and down the river. there are eight locks. and the largest ones are near where a single lock can have a trap of as much as 40 feet. as you get further down the river, the locks only bring you down another 10 feet. so every vote that leaves chicago on the way to the gulf of mexico will pass through as well. the river here was frequently used by paddleboat and steamboat

for leisure trips around the area. at the base of main street, just one block north of us, we now have a wonderful park and in the early 1900s, it was a shallow bank into the river. and that is where these boats parked or docked. i don't know if you would say docked because they just ran up onto the sand. and then a planks came out from land.w onto the and that is how passengers came in and out. at any given time, there was a dozen of these boats at least, docked there at the base of main street. and this is a representation of the columbia, which was one of the boats. withly 5, the columbia met disaster.

it had been taking a group of people from a social club from pekin up to the heights, the alfresco park. fog,s they returned in the he hit a tree stump, underwater. and the vessel sank. were almost 500 people on board the columbia that night and 87 lost their lives. and it was the worst boat disaster on the illinois river. this is a replica of columbia made by rod, above it, you see part of the whole that was recovered. and it has the ship's name on it. and in front of it, in front of the model, it is a clock that was also recovered from the wreck. ship is still at the bottom of the river. right here, we are looking at

sheet 39 of the navigational start for the illinois river. if you look carefully, in the middle of the river, you see what looks like a highway. and that is a highway for the illinois shipping canal. it is nine feet deep. it has maintained by the army corps of engineers. and it snakes through the river. and if you look outside the window at the end of the gallery and you see barges going along, they are always in the same spot. right in the middle of the highway. it is an essential part of the economy, moving materials by barge is very economical compared to moving them by some eyes on the road. so this is a vital link in our economy. i think a lot of people take the illinois river for granted. even though we live along the banks and we enjoy the fruits of

the river being here, both recreationally and from the economic importance to the region, but people don't really appreciate its integrated andory, the role it plays the unprecedented engineering feats of 1848. i don't think people really realize what a tremendous feet that was and how deeply it impacted us. both positively for an economic standpoint and in a negative way for the environment. story that we are trying to tell now is the effort that is underway to try to restore the river as much as possible. and it is aiversity wonderful part in our complex and important ecosystem. there is a legacy of the illinois river, of the

phenomenal productivity and diversity. people have been on the landscape for 12,000 years, harvesting the abundance of the illinois river. we have lost some of that with commercialization of the river, pollution of the river. upland's andn the development on the floodplains. but i think there is a new interest in restoring some of the natural diversity and resources that are so important to communities. a century ago, the illinois river was especially productive. address the most productive fishery in north america. it was the most productive muscle stream in north america. and it was renowned for recreational hunting and also for commercial hunting. and the reason had little to do with the river and more with the broad floodplain. the rivers are not that productive, that the floodplains are productive.

so the flat area along the edge of a river that is oftentimes flooded, therefore, they call it a floodplain, it can be very productive. that is where the plants grow. provide habitats and organisms and food for organisms that are eaten by other organisms. one of the big changes in the illinois waterway and river was when we started diverting waste from chicago in the early 1900s. in the 1900s, they opened the sanitary and ship canal which diverted waste away from lake michigan down the river and into the illinois river. and there was a lot of untreated invisible waste. a lot of untreated industrial waste. the slaughterhouses in chicago were dumping the refuge into the river. so it created an oxygen demand. to break down that organic matter, human waste, waste from

the slaughterhouses, it takes a lot of oxygen as the bacteria starts eating that stuff up. and as the oxygen was pulled out of the water, the upper river became an ox sick. and aip -- the fish left lot of the animal communities did really poorly for quite some time. the sanitary0s, and ship canal was opened. and within 20 years, it devastated the river. and your area was doing its part to add to the refuge. it doesn't sound like a good idea but it was cheap and easy then. and so it helped to develop these cities, have they didn't have to worry about getting rid of their sewage. they just dumped it in the river. had a detrimental effect on the river. the cousin of the problem. all the people on the

floodplains were dumping the sewage in the river. with the clean water act in the 1970's, we started focusing and effort on cleaning what went into the river. billions of dollars on waste treatment and it has had a huge impact. water quality still isn't what we wanted to be. ,here are still some challenges the last 10% is the toughest and most expensive. but we have stopped 9% of the solution problem. the day in and day out, much better than what it was in the 1970's. and we have seen a response from the fish communities along the river. there are a lot of places that have the assets that we have so it is tough to compete. but there are a lot of places that don't have a river like the illinois river, which has so much potential. so i think if we continue to do good inns for the ecology of the river and wildlife and fish

continue to come back, as we develop recreational activities along the river and educate the public with how important the river has been in the past and even more so, how important it can be in the future, i think it will be more important than it ever was. >> this weekend, we feature the history of illinois, together with the comcast cable partners. other stops ont our cities tour at c-span.org. you are watching american history tv. all weekend, every weekend on c-span3. i don't write a column that comes from the left or the right. only one who'm the does a political column that doesn't have an ideological slant. >> tonight, a new york times

columnist discusses her book, the year of voting dangerously. >> one thing i don't like about the clintons is that when they get in trouble, and donald does this too. they try to blame someone else. so when bill got in trouble with monica, the white house aides would say well, it thomas jefferson -- dead presidents, they are dragging them in. >> tonight at 8:00 eastern on cue and day. history, yale university professor emeritus john day most explores how indians, europeans, and african population converged and exchanged germs, food, and cultural practices. this is about one hour and 20 minutes. john demos: all right.