Question

Which time period in american history was marked by anti-immigrant sentiment?

Answer 1

In the years of 1840's, American history was first time marked by anti-immigrant sentiment and after that second time in the years of 1890's it was again marked.

It was also marked by anti-immigrant in 2010. About three times American history was marked by anti-immigrant sentiment.

So, these were three times when American history was marked by anti-immigrant sentiment.