Impose barriers on foreign trade
Answer:
They're all grouped together but I believe its the last one about the economic reasons
Explanation:
Lots of floods and water which created an abundance of crops
The act guaranteed the rights of African Americans and made it illegal for others to infringe on those rights. Therefore the act established the rights of the freedmen and made it a crime to infringe on these rights. This is the first time in U.S. history that the rights of African Americans were officially established.