What did the supreme court say in its plessy v. ferguson decision?

In Plessy v Ferguson (1896), the Supreme Court upheld the legality of segregated public facilities based upon race.

This led to the policy of "separate but equal" which meant that throughout the United States, public and private organizations were able disallow people of color from schools and bathrooms as long as they had separate facilities for people of color.

All of the above. - Apex

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.