What event in 1859 increased tension between the north and the south?

Two answers:

- Bleeding Kansas

- John Brown's raid on Harper's ferry

Explanation:

Bleeding Kansas resulted after congress granted Kansas the permission to vote whether it'd be admitted into the union as a free or slave state. Settlers immediately flocked to Kansas to cast illegal votes either in favor for or against slavery, resulting in a bloody conflict.

Enter John Brown, a crazy bearded guy who absolutely despises slavery, and in an attempt to start a slave uprising led a raid on a weapon depot.

This sparked fears of slave rebellions for Southern cotton planters...

the causes of the dust bowls were severe droughts,   lands became dry and hard, temperature was higher than usual, hot and dry conditions killed crops, high winds. because of those factors, the winds kicked up dry soil and created clouds of dust.