Welcome to OSM. Please don't map abandoned railways where there is no trace whatsoever (like where it is going through parking lots, buildings, etc and has been completely removed. If you are interested in mapping continuous historical routes like this, I recommend checking out OHM:
https://www.openhistoricalmap.org/

a recent development that you might be interested in is the vector version of OpenRailwayMap, which supports current rail from OSM and historical rail from OHM.
https://github.com/hiddewie/OpenRailwayMap-vector