How did the arrival of anglo-americans change life for spanish-speaking residents of the southwest?

When the Anglos started settling the southwest, they didn't want to assimilate into the Mexican culture. They didn't want to be Catholics or speak Spanish, or even learn it for that manner. As the population grew and grew and the Mexicans lost majority they started getting to the point of having to assimilate to the Anglos which led to them starting to use English even more and abandoning many of their cultural practices.