Western Railroad Discussion > CB&Q in Illinois

I have a couple of questions regarding the Burlington Route. In central Illinois, there used to be a line that split off the Beardstown line near Concord, and went south to the St. Louis area. My question is: what year did that line stop being a mainline and when was it abandoned? Finally, can anyone recommend a good website for info on the Burlington Route? I've been to the Burlington Route Historical Society website, but they don't have any links. I've searched www.railpictures.net, but there are few photos of Burlington locos. Any help would be greatly appreciated!