I need help with the critical thinking questions!!

Why didn’t the united states participate in the league of nations? the u. s. senate did not want the country to join. president wilson did not want the country to join. the league of nations was only for european countries. the league of nations had failed to prevent world war 1

Many blacks moved from the south to northern cities during world war li looking for employment. after the war, a number of them lost their jobs. why did this happen?

How did toussaint l’ouverture become a leader of the haitian colonies