One of the fundamental problems of history is scale ... A second observation to make from this map is how pervasive slavery was to the United States. In the first decades of the early republic ...

the atlas, titled Rudiments of National Knowledge, Presented to the Youth of the United States, and to Enquiring Foreigners, was meant to fill a void in educational texts about American history ...

Surely one of the most appealingly eccentric publishing ventures of the year, this volume of maps was begun by Carpenter ... tower—the 254,037-mile United States railroad network as it was ...

That progress you see in the above three maps was because of the steam engine. 1830 gave us Tom Thumb, the first U.S. steam locomotive, in Baltimore. And from there these machines took off.