Which of the following is an external factor leading to immigration to the U. S.?

During the nineteenth century and the first quarter of the twentieth century around thirty million people emigrated from Europe to the United States. Causes of these vast movements of people are explained in this paper. The three main causes were a rapid increase in population, class rule and economic modernization. Personal reasons are mentioned and discrimination against religious and ethnic minority groups are touched upon. Two inventions, the steamship and the railroad are referred to insofar as they helped the emigrants and were a cause of hardship for the poor people of Europe. Although causes of emigration fall under the heading of historical facts, they are considered in this paper as causes of suffering for the destitute of Europe who made up the largest number of emigrants to the United States.

well let's see i know a little about the fall of the roman empore but what to say i do not have a clue of what to say. (that's 28 words) i learned about it in social studies it was quite boring really my teacher talks a lot, like a lot then gives us a bunch of work sheets not too many though.( that's 60 words)i actually almost fell asleep in class of course i really like that teacher of course she is really nice. i actually don't remember much from that class i got a b without any notes (it was an open notes test)(that's 95 words) i'm wasting time but i've gone too far to stop now i'm sorry i haven't said really any thing on the topic at all sorry not sorry haha jk.(that's 125 words ) (mike drop)