How has America changed as a result of immigration?

America has changed significantly as a result of immigration.  The first Europeans were immigrants, but after the nation's founding, immigration increased.  Immigrants brought their own cultural traditions and religions.  Parts of the United States that were settled by the Irish tended to have many Catholic Churches, while places settled by the Scots had many Presbyterian parishes.  Immigrants brought their own words, dialects, and different languages.  The Germans who settled in Pennsylvania before the Revolutionary War kept their own language by living in closely-knit communities and maintaining their own German communities.  As late as 1918, it was possible to find newspapers printed in many languages in most major cities in the United States; it was only with the crackdown against "hyphenated-Americans" that this trend stopped.  Immigrants also brought in their own recipes—without immigrants, one could not order sauerkraut, tamales, sushi, or borscht.  
Immigrants also provided a labor pool for the industrialists of the nineteenth century.  Many of the railroads and canals constructed before the Civil War were created by Irish and German immigrants.  Before 1900, immigrants tended to come from eastern and southern Europe.  In the twentieth century, more immigrants came from Mexico, Asia, and the Middle East.  Most of these workers filled the need for laborers.