"It is a crime to cross the border other than as designated by immigration officials, but there is no separate crime for being unlawfully present in the United States," Chin said. "...it’s easy for such individuals to run into separate criminal problems even beyond their method of entry, such as filling out an employment eligibility form to get a job when they aren’t eligible to work. Unlawful presence is not a crime. It is a civil violation. You don't go to jail or receive any other criminal punishment for being in the country illegally — you get deported." http://www.politifact.com/florida/statements/2017/mar/15/florida-conference-catholic-bishops/being-united-states-unlawfully-crime/

So it appears to be illegal to cross the border without authorization and for filling out an employment eligibility form when not eligible. And over staying a temporary visa is also a civil infraction. You seem to be making a somewhat semantic point.