What could be a problematic effect of granting states to much power to pass their own laws?

How did slavery end in the united statesa. it ended with the emancipation proclamationb. it ended when the union won the civil warc. it ended with the fifteenth amendmentd. it ended with the 13th amendment

Which of the following was not a result of the industrial revolution in europe? a. the rise of a middle class b. the urbanization of europe's society advances in agriculture and industry d. the decline of europe's large cities

Pls me! the black codes were various state laws in the south concerning african-americans which of the following statements about the black codes is not accurate. a. the black codes protected the civil rights of african-americans. b. african americans who cannot afford to pay a fine could be jailed and then be hired out to anyway person who could pay the fine. c. some southern states passed laws that prohibited is african-americans from voting or serving on jury‘s. d. the black codes were designed to force african-americans into a condition of near slavery.