This is the #1 issue I have with people who want to try and compare the immigration of Germans, Irish, Italians and other Europeans in the past. There was a much stronger emphasis on assimilation to American culture than what appears to exist today. If people want to have an honest conversation, which many do not, they would need to include this. Something as simple as saying Americans need to be better than they were 100 years ago in welcoming those from foreign lands, but at the same time, those from foreign lands must take very seriously the goal of assimilation into American culture. This position has no logical argument against.
The #2 issue, for me at least, is also being honest about the cost of assimilation for refugees into American towns and cities. The resources that are provided today simply did not exist back then. It was up to the local community to provide and nurture new immigrants. Now this does not mean that providing for refugees shouldn't happen. America has improved and learned from it's past...at least I hope so. But it still does not change the fact that because these services are being provided....comparisons to past immigration are not the same.