Answer:
They were banned.
Explanation:
United States passes legislation banning the slave trade.
One very negative consequence of increased feelings of nationalism after WWI was the rise of fascism or so-called national socialism in countries like Germany and Italy. These governments appealed to nationalism and blamed such groups as the Jewish people for their economic problems in the late 20's and early 30's and also believed they had the right to invade and control other countries.
Compared to time in earth's history before humans appeared, rates of soil erosion are "higher", due mostly to the fact that some human activity associated with building structures adds to this erosion.