What change and government policy took place at the end of world war one

At the end of World War I, due to mounting war debts, the recently established Income Tax was drastically increased from a top marginal rate of 15% in 1916 to over 75% in 1918. After the war ended, the Government drew down the military and eventually changed its policy towards income tax, bringing it back down into the 20s.

It is NOT Income taxes were increased to pay off the war debt. I believe it is The federal bureaucracy was desegregated.