Leaders of the southern states that seceded from the union were most concerned about which of these problems?
a. the loss of states' rights to control their own laws
b. the power of the abolition movement to influence southern landholders
c. the use of tax money to purchase large new territories in the west
d. the unwillingness of army leaders to remove native americans from the southeast

a. the loss of states' rights to control their own laws

Explanation:

The main problem that the southern states had with the Union and the main reason for them to seced from the union was the fact that the Union wanted the federal government to have authority and last word over all of the States that entered the union, this basically gave power to the federal government of free will and the States should have to obbey what the federal government said, that was why they felt they were loosing control over their own laws.