How does the oil can in 'The Wizard of Oz' relate to US history?

Answer 1

The unemployment and dehumanization of workers may be a way of relating the oil can in "The Wizard of Oz" to the history of the United States of America.

Specifically, the Industrial Revolution opened up greater employment opportunities in the cities than in the countryside. People poured from the rural areas into crowded, unsanitary conditions in the growing urban slums. They spent long hours working at low pay, under miserable conditions, for self-serving employers. That the Tin Woodman needed an oil can to get him going again symbolized the suffering and unemployment from the U.S. Depression of 1893 and the meeting of human needs through subhuman living and working conditions.