Look at racial maps of many American cities, and stark boundaries between neighboring black and white communities frequently denote an impassable railroad or highway, or a historically ...

Even in 1857, travel was easier, thanks to the railroad system. These maps don’t just show the rapid pace of technological progress, however. They also show how that progress advanced unevenly ...

Find out more about what this space is all about here. This map shows the reach of railroad and telegraph infrastructure in New England in 1854. Notched lines signify extant railroads.