How did railroads affect empire building in afro-eurasia between 1860 and 1918?

The expansion of the railroads in the late 1800s was instrumental in helping the US economy boom.   It did this in two ways. 

First, the railroads created a tremendous amount of demand for goods and labor on their own.  As the railroads were being built, they needed huge numbers of people to build them. 

while it was true that the cotton gin reduced the labor of removing seeds, it did not reduce the need for slaves to grow and pick the cotton.

explanation:

before eli whitney's invention of the cotton gin, picking and cleaning cotton was a slow, labor-intensive job. workers, usually slaves, had to pick the seeds from the cotton fibers by hand. this invention made it possible to grow large amounts of cotton on big farms and make money.

a variant spelling of the word dote (british)