Atlantic Coast Line - My Granddaddy went from wood to coal to diesel with that line and was the first engineer of The Champion with the ACL's first diesel engines, E3-500 and E3-501, in November of 1939. The day he retired I sat in his lap in the cab and he took me for a little ride and I got to pull the horn lanyard, 3 longs-one short- and one long for a crossing.
E3-500 was wrecked and rebuilt as an E8 but E3-501 is still alive in Salisbury, NC at the Spencer Shops museum. It was retired with 6,250,212 passenger miles, most of any passenger engine ever built; or so I was told. I visited it with my Mother, daughters and my grandson two years ago.
They brought it out of the roundhouse for us and I sat in the engineer's chair with my grandson on my lap 50 years after My Granddaddy had done the same with me.