>>949932It was a GM&O branch line that connected to their main line, the former New Orleans & Northeastern, from New Orleans to Jackson.
The right of way was built and paid for to get lumber from the north shore to Hammond and the paper mill at Bogalusa, but ran passenger service well after logging stopped.
Southern ran trains along the main line, but didn't actually own it, I think, until GM&O merged with the Illinois Central. That was in the 70s, so I'm assuming that's when and why the Covington branch was abandoned.