In the early days of the railroad, huge tanks were built along the routes where the steam engines could stop and refill by pulling, or jerking, a spout into place, allowing the water to flow from the tank to the engine.
The tiny community that grew up around the tank was called a “jerkwater” town.
A “one-horse” town was so small, one horse could do all the work and transportation for the entire community, so it was about the size of a jerkwater town.
