Answer:
Many activists joined effort to reform local government, public education, medicine, finance , insurance , industry, railroad track , churches, and many other areas. Progressive transformed, professionalized and made "scientific" the social sciences, especially history, economics, and political science.
This is mostly due to checks and balances. For example, the veto. The president can veto a bill, but if 2/3rds of the senate and the house both want the bill to pass, then the president cannot veto this bill.
C. Because there was no branch to enforce these laws
When we were under the AOC, they wrote it so that the state governments had all the power, while the Federal government had very little. Since they were afraid of a tyrannical figure ruling over them, they made it so that there was no executive branch. Only a legislative branch. Because of this, they could make all the laws they wanted but no one could make the states follow them.
The second World War greatly reshaped ideas about national identity in America, especially for first-generation immigrants, second-generation immigrants, and African-Americans. During the war - and in the midst of the war effort - immigrants and African-Americans were welcomed into the armed services and, also, in areas of production where support was needed. Many Americans, during this time, were able to somewhat relax or surrender their prejudices. Also, for immigrants and African-Americans, they often felt they were part of American industry and service for the first time.
