<Ul> <Li> Alabama, a slave state, enters the union . </Li> <Li> Missouri again petitions for admission to the union . </Li> <Li> U.S. Representative James Tallmadge, Jr. of New York submits an amendment to the legislation for the admission of Missouri which would prohibit further introduction of slaves into Missouri . The proposal also would free all children of slave parents in Missouri when they reached the age of twenty - five . The measure passes in the House of Representatives but is defeated in the Senate . </Li> <Li> Representative Thomas W. Cobb of Georgia threatens disunion if Tallmadge persists in attempting to have his amendment enacted . </Li> <Li> Southern Senators delay a bill to admit Maine as a free state in response to the delay of Missouri's admission to the union as a slave state . </Li> </Ul> <Li> Alabama, a slave state, enters the union . </Li> <Li> Missouri again petitions for admission to the union . </Li> <Li> U.S. Representative James Tallmadge, Jr. of New York submits an amendment to the legislation for the admission of Missouri which would prohibit further introduction of slaves into Missouri . The proposal also would free all children of slave parents in Missouri when they reached the age of twenty - five . The measure passes in the House of Representatives but is defeated in the Senate . </Li>

Which statement is most accurate about the causes of the civil war