Which factor was responsible for the change in
population from 1860 to 1910?

Hello, I Am BrotherEye

American urban population growth from 1860 to 1910 resulted mainly from a large influx of immigrants.

Explanation:

The immigration from 1901 to 1910 had a greater effect on the USA than the immigration from 2001 to 2010.

This statement is true because the USA's foreign-born population is 50 million or 14 % of the total US population of 312 million according to the 2011 American Community Survey.

By 1910the immigrant share of the population peaked at 15 %. The foreign share of the population fell to 5% in 1970 and by 2010 it was around 6 %.

lincoln declared that slavery should not be allowed to spread into the new states, and of course this angered the south at the time.

a case involving the laws of a single state.