I NEED YOUR HELP

First of all, hello american forumers. I need your help cause I have to do a project on: the growth of cities in America and its immigrant population "75% of the population of America'sten largest cities were either foreign-born or only a generation removed from foreign born parents between 1880 and 1914" The problem is that I don't know how to focus it. I'm lost I don´t even know which are the ten largest cities in the USA (L.A., NYC, ?, ?...) nor where can I find maps seeing the growth of them and how immigration affected it, which are the most common nationalities in each one, the different districts.. and to find it on the net results really really difficult, and more for me. Im Spanish. well, if you could help, please post something thank you anyway>