show how immigration has helped to shape America and describe some of the barriers immigrants have faced in their struggle for equality

i'm stuck on this question

my teacher said the best answer will begin with colonists and go up through Irish/ Asian immigration of the 1840's and 1850's. The starting point will influence your description of physical problems of early settlers as the ethnic hostility faced by later groups. For a complete answer you should discuss forced migration of African Americans.
please, please give some helpful information,. thanks

Check out these sites.

http://www.google.com/search?source=ig&hl=en&rlz=1G1GGLQ_ENUS324&q=history+immigration&aq=f&oq=