Explain two reasons for the expansion of slavery in the South after 1800.

One of the primary reasons for the reinvigoration of slavery was the invention and rapid widespread adoption of the cotton gin. This machine allowed Southern planters to grow a variety of cotton - short staple cotton - that was especially well suited to the climate of the Deep South.

Explanation:

b. second continental congress

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.