Noncitizens

Free to read here, from Project Gutenberg.

The Old World in the New

Edward Alsworth Ross

They Who Knock at Our Gates: A Complete Gospel of Immigration

Mary Antin, also an audiobook

Aliens or Americans?

Howard B. Grose

On the Trail of the Immigrant

Edward Alfred Steiner, also an audiobook

Americans by Choice

John Palmer Gavit

The Alien Invasion

W. H. Wilkins

The American Spirit in the Writings of Americans of Foreign Birth

Robert Elihu Stauffer

Some Immigrant Neighbors

John Robertson Henry