Children's Rights Movement in Children's Literature
The Children's Rights Movement really got going during the Industrial Revolution in Britain (1760-1840), when loads of kids worked in factories. Yep: tiny little kids, as young as six, were forced to labor for long hours each day.
Finally social reformers began speaking up and saying that it just wasn't right. Kids, they argued, aren't adults; they're just not cut out to work all day in terrible conditions, lifting heavy loads and performing tasks that are suited for adults.
The Children's Rights Movement played a big part in establishing a distinction between "children" and "adults." (Check out "Concept of Childhood" for more on that.)