Percy to Cairo
At Murphysboro, the GM&O depot there is still standing and is now used as a restaurant; furthermore, Murphysboro used to house major GM&O shops until the town was hit by a tornado in 1925.
The line itself continues southward from Cairo along the IC via an interchange north of Cairo that carries the GM&O line on the IC's Cairo Rail Bridge.
As for abandoned railway lines within Cairo itself, while there aren't any grandiose viaducts or steel trestles that used to line Cairo, there are a number of abandoned yards and other facilities at Cairo. Of special note are the visible remnants of two roundhouses; one just west of the intersection between 18th Street and Commerce Avenue, and one to the direct west of the intersection between Washington Avenue and 2nd Street. Considering how there weren't any bridges that brought rail lines directly through downtown Cairo itself, it's obvious that these were all end-of-the-line engine servicing terminals for their respective railroads.
Tghis is the former Gulf Mobile and Ohio, the orginal line before the 1947 merger with Chicago and Alton. Unlike the Alton Line, this line used searchlight signals instead of color position lights. There were fewer crossarms on the pole line. When Illinois Central merged with Guklf Mobile and Ohio in1972, this line was deemed surplus and was abandoned, first south of Murphysboro and then south of Percy. Postions still are in servcie to serve coal mines and are actually connected to the rest of the system only by trackage rights.