Where can I find illegal immigration statistics from 1920s all the way to the 2000s?

From 2000 onwards to present I have the statistics for ilegal immigrants but its very very hard to find any before 2000...Im writing about illegal immigration and I need a buildup so I thought I'll write about the history of illegal immigration

I need statistics from 1900s onwards

You're not going to be able to get them, because "illegal immigration" didn't even mean the same thing 100 years ago. It used to be that it was legal for anyone to immigrate, no quotas, no applications, etc., as long as they weren't from a prejudiced against ethnic minority. Does it help you to know that so many thousands of Asians, for example, tried to come to the U.S. to join their legally emigrated families, but were denied because we openly stated that Chinese people were bad? What about during the 50s, where Congress complained that there were too many illegal immigrants, so the executive branch just made everyone legal?

I strongly encourage you to study immigration history, and you will see that this myth that we have, that immigration law today is the same as it always was, is so unbelievably false. If you look historically, you can see how immigration law was openly used to chose which nationalities were 'clean' and which were 'unclean' (again, look particularly to Asian immigration patterns and laws).