Progress on the nation's second transcontinental railroad slowed in 1873. The Northern Pacific's proposed middle--the 250 miles between present Billings and Glendive, Montana--had yet to be surveyed, and Sioux and Cheyenne Indians opposed construction through the Yellowstone Valley, the heart of their hunting grounds. A previous surveying expedition along the Yellowstone River in 1872 had resulted in the death of a prominent member of the party, the...