People had to stop at Ellis Island, show the proper papers and go through health checks and other checks before being allowed into the country. Of course there were legal entries and ILLEGAL entries.
The fact of the matter is immigrants to this country always had to go through a certain process to become Citizens or legal residents, AND they all showed a willingness to do so. That is the difference between todays ILLEGAL law breaking parasites and the immigrants of the past.
I think we'll discover that there wasn't always immigration control and an INS and an Ellis Island entrypoint.