Under the Missouri Compromise of 1820:
a. slave states gained a two-seat advantage in the U.S. Senate.
b. Missouri agreed to gradual emancipation of slavery in exchange for admission to the Union.
c. Ohio became a free state to balance the admission of Missouri as a slave state.
d. the remaining Louisiana Purchase territory was divided into slave and free zones.
e. Congress banned slavery in any new territory that might ever be added to the United States./search?