How did the federal government aid railroad construction in the 1850s and 1860s?
Land was given for free to railroad companies
The federal govenment helped railroad companies by granting them free land.
Indian Wars were fought partly so as to satisfy the needs of railroad companies, thus they led to the Yellowstone expedition which failed and led to the bankruptcy of the Cooke brothers. The Black Hills that followed were due to the will to build a second transcontinental railroad line. It proved a failure with Custer's defeat and death at Little Big Horn in 1876 in Montana.