What changes took place in the southwest during the 19th century?

We don't do homework for you on this site. If you do a bit of research on this topic and come back with a more specific questions on the topic then someone might be willing to answer.

Please read this announcement (https://www.askmehelpdesk.com/math-sciences/announcement-u-b-read-first-expectations-homework-help-board-b-u.html) regarding homework.