Final answer:
The end of the Progressive Era in the Roaring '20s was marked by shrinking income disparities, civil rights reforms, reduction in business taxes and government spending, and a decline in union membership.
Step-by-step explanation:
The conditions in the Roaring '20s that marked the end of the Progressive Era include:
- Shrinking income disparities and growing economic equality: The economic boom of the 1920s led to a rise in living standards for many Americans, and the gap between the rich and the poor narrowed.
- Civil rights reforms ending segregation and discrimination: While progress was made in some areas, such as women's suffrage, racial discrimination and segregation persisted, particularly in the South.
- Reduction in business taxes and government spending: The 1920s saw a conservative shift in economic policy, with lower taxes and a reduced role of government in the economy.
- Legislative successes that rendered unions obsolete: While union membership declined in the 1920s, it was not due to legislative successes, but rather a combination of factors including the post-war economic downturn and employer hostility towards unions.