Answer to Question 1
Americans were more willing to believe that immigrant outsiders were the more likely culprit for their other-ness, and therefore were more prone to blame and retribution for crimes. During the Haymarket riot, recent immigrants were blamed, and even afterwards, their actions were described as un-American, a term that promotes ethnocentricity and fear of difference.
Answer to Question 2
Manifest destiny was the belief that it was acceptable for the U.S. government to claim all land as far west as the Pacific Ocean no matter who occupied it or held power over it. Points that the student could expand on would be that Manifest Destiny gave Americans the right to expand westward. The forceful claim of resources and land by homesteaders, railroads, foresters, and miners were all often backed by new laws that gave settlers rights, while taking them away from Native Americans.
Students may also mention the Dawes Act that limited and reduced the size of Indian lands.