The narrow-gauge East Tennessee & Western North Carolina.
My parents grew up just a few miles away from this line and were in their teens when the 3-footer folded up but retained some standard-gauge tracks. Neither recall ever seeing the narrow gauge trains, but both recall seeing steam in the nearest town, up until the early 60s when they left the area.
My folks always took my brother and me for trips to the area to visit all our relatives, usually once a year. I would see the ET&WNC diesels running around Elizabethton, Tennessee every now and then as well as the Porter fireless 0-6-0 that was running as late as the early 1990s. A few times, we even went to Tweetsie RR in Blowing Rock, NC, home to former ET&WNC 4-6-0 # 12.
My first cab ride on a locomotive ever (at the age of 11) was on Southern RR 630, which used to be ET&WNC 207.
Funny thing is unlike many of you, I have almost no interest or connection to the railroad that ran through my hometown, the Seaboard (SCL as a kid, CSX when I left Florida for good). I live a couple of miles from what on paper was a transcontinental RR (LA to Jacksonville, FL) but was treated like a branchline. The trains were sparsely ran and not very appealing. Passenger traffic ceased when I was 2 years old and didn’t start up until the 90s for a few years before I left the area for good (and died again, after hurricane Katrina). There was no running steam closer than a 5-hour drive in any direction (Disney or Atlanta was each the same distance) and Southern/NS steam hardly ever got detoured through there. In my lifetime, steam only came FOUR times: SRR 4501 on a ferry run to Jacksonville, 4449 with the Freedom Train, Clinchfield # 1 on a ferry move somewhere and S&A 750 detouring past a derailment on the SRR. I only ever saw 4501 and 4449. The other two moves were not announced until the day after they’d taken place.
So, other than seeing the Freedom Train just before my 7th birthday, I have few fond memories of trains from where I grew up.