And how many millions of Americans were out of work back then due to massive layoffs to make room for those immigrant workers?
And I can't speak for your ancestors, nor mine really, but I suspect none of them received free food and medical care and I suspect it was expected and demanded they obey the same laws as other citizens and take responsibility for their families and themselves.
Since you were speaking of immigrants. It is my understanding these H1B are not immigrants - just foreign workers.
Me ---mine came before the turn of the century when there was lots of available land for homesteading so they didn't take anyone's job but created towns and farms of their own. We don't have unowned land sitting around anymore so immigrants compete for jobs with Americans or end up on welfare. When unemployment is climbing we should put Americans first.