The document discusses the Transcontinental Railroad in the United States in the mid-1800s. The US government wanted to build a railroad connecting the east and west coasts. Many eastern states wanted to be the starting point, while Congress chose Chicago. However, Nebraska needed to become a state first to make the route work. The South wanted the Missouri Compromise repealed so that Nebraska could join the union as a slave state, further exacerbating tensions between the North and South over the issue of slavery and western expansion.