What effect did factories have on the population of cities in the 1800s

The Industrial Period happened between 1760-1840's. During this time period, people replaced workers doing manual labor. Because of this, people lost their jobs or quit, because machines were doing it, so why should they? The advent of Technology and Agriculture advancements improved the nutrition of people so eventually, the population grew as women and men have more time to take care and build their families.