Final answer:
Child labor in factories in western Europe and the United States declined by the end of the nineteenth century due to the implementation of child labor laws, increased demand for child education, and a preference for adult workers.
Step-by-step explanation:
Child labor in factories became less common in western Europe and the United States by the end of the nineteenth century due to a combination of factors:
- Implementation of child labor laws: Governments in these regions passed laws to ban child labor, motivated by concerns over the safety and well-being of children in the workplace.
- Increased demand for child education: Compulsory education laws were enacted, which required children to attend school rather than work in factories.
- Preference for adult workers: Mechanization of the workplace reduced the need for child labor, and employers began to prefer adult workers for more skilled tasks.