Underground Railroad

When you think of the underground railroad, one of the places that comes to mind is Upstate New York. Harriet Tubman lived most of her adult life outside of Syracuse and many escaped slaves passed through the area on their way to freedom in Canada. When you think about a more literal underground railroad, you have to think of New York City and its hundreds of miles of subterranean railway. I was unaware of this until I saw a poster for a screening of The End of the Line in the men's room at Clark's Ale House, but the city of Rochester, New York used to have a subway system. As the documentary states, Rochester is the smallest American city to ever build and abandon a subway system. I'm not exactly sure why the abandonment disclaimer is included. Is there a smaller city that has yet to abandon it's subway system? Were cities like Boston or San Francisco smaller when they built their subways than Rochester was when it built its subway in 1927? I'm not going to make it to the screening of The End of the Line, since it's out in a suburb of Rochester, but I'd really like to see it sometime.