Which action by peesident andrew johnson had the greatest impact on recunstruction

What is the relationship of the letters n.y.l> w.c to the new york infirmary for women and children

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.

What from the columbian exchange had perhaps the biggest impact on the world?