"I bet you live close to the station, where the trains are."
Waltham railroad crossing - Credit: the(?)
Prior to the introduction of railways, well-off families tended to live in town centres whilst the less prosperous (and non-white) were driven out to the margins. When train-tracks were laid down, they provided a physical demarcation of this social divide, giving rise to the expression ‘the wrong side of the tracks’. Those on the poorer side were disproportionately affected by soot and smoke from trains and the industry that sprang up around stations, which had the effect of keeping house prices low and the neighbourhoods undesirable.