Yes, Your Ancestors Probably Did Come Here Legally — Because 'Illegal' Immigration is Less Than a Century Old - No Visas Were Required Until 1924
Los Angeles Times
There were no federal laws concerning immigration until 1924. When a massive influx of new immigrant groups came at the turn of the 20th century — Italians from Southern Europe and Jews from Eastern Europe — a backlash developed. A new law required for the first time that immigrants to the U.S. have visas, introducing the concept of “having papers” to American immigration policy.