Hey there Sam,
Your question states: According to Figure 24-1, between which years was the number of immigrants to the United States the least? Based on the upload, I see that in the year 1861, it was very low. And then from 1866 and on, that's when there were alot more.
Hope this helps you Sam. And I see that you have Doulingo open, I hope you progress in what ever language you are learning :)
Have a good day.
~Jurgen
