It means that the person is mentally ill but is still responsible for the crimes that were committed.
After America was established, were similar to multiple eras with migration. Firstly, there was a language barrier. Many immigrants during that time had no knowledge of speaking English. If the immigrant had no body to rely on, like friends or family, they would be said to handicapped. Of course, many Americans highly disliked immigrants. The Americans didn't like immigrants because they felt like they took their jobs away from them, and did not respect their American traditions.
Generally speaking, "<span>a. The British moved most of the indigenous peoples onto lands with poor quality," although many stayed where they were, and many were also killed. </span>