If you had been on the right side of the train coming into Memphis you would have had a good view of the River and its bridges as you came in on the foot of the Bluff. Just south of Memphis station is Grand Crossing where the CN crosses everybody else that operates into Memphis. I think it is now 4 tracks E-W for the others plus 1 track N-S for CN. It is now signaled. In the past, it was 6 tracks by 4 tracks and a four way stop. Since NS and CSX come in from the east and both terminate at yards east of the crossing, the only likely move by either of them would be some form of transfer mover or local. The most likely delay would be either UP or BNSF. While UP terminates in Memphis, their yard is east of the crossing. BNSF runs through, also the BNSF line is double track but the bridge across the river is single track, so it could possibly have been a westbound BNSF train waiting for an eastbound to get clear of the single track.
A note of history: When the first Mississippi River bridge was built (opened 1892 and still in use by BNSF) the city dedicated a street right of way from the east end of the bridge to some point past where the NS, then Southern, came into town and allowed each railroad operating into Memphis to lay one track on it. There is not roadway. Tracks only. That would have been L&N, NC&StL, Southern, KCM&B, KCFS&M, SSW, SLIM&S, Y&MV, ICRR. I don't know if it ever had more than 6 tracks. For a quick who's who, L&N and NC&StL are both CSX,, but the NC line into town is gone; Southern is NS, KCM&B and KCFS&M were the parents of the Memphis Bridge company both became Frisco, now BNSF; SLIM&S, commonly called the Iron Mountain, became part of the Missouri Pacific, and along with SSW (Cotton Belt) now UP, ICRR and Y&MV now in CN.