2. After WWI what was Tulsa's Greenwood District known as?

After WWI Tulsa's Greenwood District was known as Black Wall Street.

Explanation:

In the United States, the Black Wall Street is the most commercially successful and affluent majority African-American communities.

The First World War is primarily called the Great War prevailing in Europe from 1914 to 1918. This great war was fought in Europe, Asia and Africa on three continents and sea, earth and sky.

This war lasted for about 52 months and it was a life-changing experience for the generation of that time.