The Industrial Revolution came about when machines started to replace hand made products. Businesses found they could be much more efficient using machines to do the majority of the work in production. Cities started to see factories develop and become a vital part of the economy. Workers saw their wages increase and their overall well-being improve.
The textile industry was on the forefront of the industrial revolution, with factories and mill building popping up in many American cities. The factories and mills were successful at building up the economies and as more cities saw this, more cities started to develop in the same way.