When parents are unable, unwilling or unfit to care for a child, the child must find a new home. In some cases, there is little or no chance a child can return to their parents' custody, so they need a new permanent home. In other situations, children only need a temporary home until their parents' situation changes. In any case, the children need somewhere to stay until a permanent home is possible. Hundreds of years ago, providing this temporary home fell informally to families, neighbors and often to the church. As cities grew larger and more and more children in a community ended up in this unfortunate situation, government institutions took up much of the responsibility.
Over the past hundred years, the trend in North America and Europe has shifted away from orphanages and towards foster homes. The underlying philosophy of foster care is that children are better off, emotionally and psychologically, in a home environment, with someone filling the role of a parent. The logic is that with one or more foster parents taking care of a smaller number of children, the child should have more of the attention and love they need to grow into healthy adults. Today, there are roughly half a million U.S. children in the foster care system.