Which historical event most caused the US urban population to climb from 6 million to 44 million between 1860 and 1910?

A. Union defeat of the Confederacy in the US Civil War

B. discovery of gold near San Francisco, California

C. United States winning the Spanish-American War

D. development of factories during the Industrial Revolution

Respuesta :

The historical event that caused the United States urban population to climb from 6 million to 44 million between 1860 and 1910 was the development of factories during the industrial revolution. Money was to be made and this made people rush to the cities. They also had popular entertainment attractions that brought people in such as vaudeville amusement parks, etc. 

Answer:

development of factories

Explanation: