Verdingkinder
Between about 1800 and the1960s, children from poor families were placed in other families. The idea was that they would get a better education there. In most cases, though, they were placed there because they were seen as cheap labor. These children were known as Verdingkinder. In German, Verdingung meant that the child was placed at a different family, in foster care. They had to do hard work, and got little or no pay for it. This happened mostly in summer, when there was a lot of work. It dids not only happen to poor families, but also to those where the authorities believed there was a problem (siuch as single-parent families, or families from ethnic minorities, such as the Yenish people. It happened to children in Switzerland, western Austria, and the souh of Germany.
It also happened in other places. When it happened in Sweden, Astrid Lindgren wrote a story about it. The story is called The Red Bird, in English.