What is one reason that the number of children working in factories increased in the late 1800s

During the late 1800s, the number of children increased in the factories because of poverty. Many families during the late 1800s were living in poor condition with minimum wages along with long shifts which led them to put their children in factories so they could earn little money for the family. Children worked in a dangerous situation, especially in the cotton mills where they would reach under the machines to get the cotton fibers.  

a historian is attempting to study how the puritans affected society in new england