What are black blizzards

A black blizzard is a dust storm especially in the dust-bowl area of the U.S.

Explanation:

During most of the 1930s, the Great Plains region was devastated by drought and high winds. Howling across the Great Plains, these winds whipped up the soil of the over-farmed land and created blizzards of dust. These “black blizzards” were so thick and blinding that daylight seemed more like dusk.

Explanation:

a system of cooperative federalism emerged, as the powers of the federal government expanded.