Sitting in the Peach City Diner (delicious hand cut french fries!) with a crowd of adolescent missionaries and barely postpreadolescent priests, it's hard to imagine that the first, great physical link between the Atlantic and Pacific coasts was sealed by a solid gold railspike, driven with a silver hammer just a few miles east of here.
Construction began in the midwest, at Davenport, IA, and at San Francisco Bay on the Pacific coast. 1900 Miles of contiguous track from Omaha to Oakland opened for business on 5/10/1869. The South was beaten, and slavery gone. The Indians, still capable of mounting serious resistance in 1863 when construction began, were mostly finished by the time the road was done.
The native American peoples were nearly wiped out by smallpox, measles, and other imported diseases and conditions against which they lacked immunity. The historian Francis Jennings estimates death rates from the Euro plagues at around 90 percent, or the same rate of mortality that was documented in Mexico at the time of contact. Violence was the destiny of survivors of the plagues, and their fate was sealed when Custer's command was snuffed out near Deadwood City, SD, in 1876. Even more, though, mechanized transport, linking the coasts, opened the west to exploitation and Euro American penetration on a revolutionary scale.
Already the sustenance and habitat of the natives was being altered by aggressive, ambitious, and prophetic capitalists. They engineered systematic destruction of the vast herds of bison, so as to "open" the west to "settlement" by a new set of humans and their bovines. And they would demand rairoads, to haul their cattle, and the bankers and finance guys, the consultants and stock waterers would enjoy a golden cascade of riches. And they did.
But think of it: before the Civil War the only way to get to Oregon from the east was to take a train to St Louie or Iowa, then get off and walk. Through wind and weather over a barren plain, two mountain ranges, and a large desert. By 1869, you could take a four day Pullman's Palace sleeping car, if you had the dough, and ride in comfort and security from most anywhere northeast of the Mississippi.