Oz = oz., an abbreviation for ounce
Kansas = the hardships of life
Cyclone = the financial panic of 1893
Silver slippers = silver as a monetary standard
Yellow brick road = gold as a monetary standard
Emerald City = the fraudulent world of greenback paper money that only pretends to have value
Dorothy = the naive and simple American people
Tin Woodman = the dehumanized industrial worker
The Scarecrow = the farmer
The Munchkins = the ineffectual ordinary citizens who are controlled by politicians and big money