Why did people immigrate to the united states in the nineteenth century and two difficulties that immigrants faced leaving their new homes and starting a new life in the united states?

from the conditions of the working class in england by friedrich engels,the main idea is :

herodotus taught this. herodotus was an ancient greek historian who was born in halicarnassus in the persian empire. he is known for having written the book the histories, a detailed record of his "inquiry" on the origins of the greco-persian wars.