How did immigration change America in the late 1800's

Which one of these best describes an interest group

When president johnson vetoed a law that would extend the freedmen’s bureau, congress reacted by supporting the veto and closing the freedmen’s bureau. writing a new law to show support for the black codes. overriding the veto and expanding the agency’s powers. drafting a law to prevent african americans from voting.

Which physical feature minimizes population density in northern africa?