During the 1850s, the only land added to the United States was a barren stretch of some 30,000 square miles south of the Gila River in present New Mexico and Arizona. This Gadsden Purchase of 1853, in which the United States paid Mexico $10 million, was made to acquire land offering a likely route for a Pacific railroad. The idea of building a railroad linking together the new continental domain of the United States, though a great national goal, spawned sectional rivalries in still another quarter and reopened the slavery issue.

During the 1840s, rails extended beyond the northern eastern and Middle Atlantic states, and mileage increased more than threefold, reaching a total of more than 9000 miles by 1850. Expansion was even greater in the following decade, and by 1860, all the states east of the Mississippi had rail service. Throughout the 1840s and 1850s, railroads cut deeply into the freight business of the canals and drove many of them out of business.

Across the Lower South, the iron horse, symbol of a speeding new industrial age, dawdled at the pace of the largely preindustrial communities it connected. A modern jet races over the approximately 650 miles between New Orleans and Charleston in a single easy hour. A modern automobile speeds over the approximately 750 miles of superhighway between the two cities in a single hard day. Mid-nineteenth century trains could meander over the approximately 1000 miles of tracks between the two centers in a long, unforgettable week – if one made connections.

The popular image of Thoreau as cold and negative was created in large part by his friend Emerson, who saw Thoreau as stoic and therefore overemphasized these qualities in both his eulogy and in his subsequent editing of Thoreau's letters. There is no question that Thoreau could at times be crusty, abrupt, and cantankerous. His friend Caroline Sturgis Tappan once said that he "imitates porcupines successfully." He loved to deflate the pompous and disturb the conservative. But on the other hand, he was a loving son and a thoughtful brother.