Henry David Thoreau had decidedly mixed feelings about the railroad that reshaped America during his lifetime and, quite literally, shattered the tranquility of his Walden Pond cabin several times a day. “We do not ride upon the railroad,” he groused in Walden, “it rides upon us.” He relented, at least a little, elsewhere in the essay: “‘What!’ exclaim a million Irishmen starting up from all the shanties in the land. ‘Is not this railroad which we have built a good thing?’ Yes, I answer, comparatively good, that is, you might have done worse.” But his opening turn of phrase offers an apt point of departure for this chapter. A nation builds railroads and that network, from that point forward, builds the nation. This is true for both nations, but in a simpler and more dramatic way for the United States, which matured in tandem with rail transportation.