How has the definition of mental illness changed over time?

The definition of mental illness has changed over time. In the 1800's people weren't aware of a mentally ill person they just thought oh that person is crazy and they would send them away or try to cure them. Now in present time I feel that people are more accepting but also at the same time aren't. Most people with mental illness are judge and people think they are crazy or "Not right in the head. There are also people who help people with mental illness and accept it. The definition of mental illness has changed it went from crazy and get sent away to we accept your illness and will help you through it.