Manifest destiny was a belief in the 1800's that the U.S was destined by God to expand across the continent, from the Atlantic to the Pacific Ocean.
After the annexation of Texas in 1845, most Americans belived the entire continent belonged to America. The country was seen as bringing light to the darkness.
Canals were popularly used for transporting goods until the 1860's when railroads rapidly changed how we transport items. This was mainly a good transportation route in winter because the canals may freeze.
Not all things with the railroads were good though. Often there were Native American snipers, raids, livestock rustlings, scalpings, and burnings all around the railroad right of way.
In 1862, Congress passed the Homestead Act which offered up to 160 acres of free land to settlers. The law passed three steps: file an application, improve the land, and file for deed of title.
Anyone who had never taken arms against the U.S government, including, freed slaves, was 21 or older or the head of the family, could file an application to claim a federal land grant.