Again I'd suggest MultiModalWays (http://www.multimodalways.org/archives/rrs/rrs.html
" onclick="window.open(this.href);return false;)... I've made extensive use of the library of track charts, timetables, system and division maps, and more in my attempts to model various lines in a railroad simulation program, and gotten sidetracked more than I can count (damn ADD... Oh look a chicken!) with just following old lines through Google Maps once I see what they were within those documents.
Specifically http://www.multimodalways.org/docs/rail ... 1-1998.pdf
" onclick="window.open(this.href);return false; shows CSX and NS pre-merger (the thin red and green lines respectively) and how the Conrail lines were split (the thick red and green lines
). But you can also find system maps for CSX (as well as B&O/C&O etc) and NS before the CR split - just look for maps, charts, and timetables before 1999.
You've said the more detailed the better in both cases, are you just looking for cities passed or actually where within those cities the lines were? If you're looking for the latter you're not going to find it in one map - you'll have to pull maps from each area, but the system maps Scot and I have pointed you to will give you an idea of where to look.