The event of the 1920's which best reflects the conflict in American society between science and religion was (2) the Scopes trial. The Scopes trial was a legal case where a substitute high school teacher was accused of violating Tennessee's Butler Act, where it was made unlawful to teach human evolution in any state-funded school.
One of the main goals of the March on Washington on August 28, 1963 was for civil and economic rights for African-Americans. This was where Martin Luther King Jr's famous speech "I Have a Dream" was delivered and this was one of the largest political rallies to ever take place in the United States. This march helped to pass the Civil Rights Act and led the path to the Voting Rights Act.
Advances in medicine slowed death rates, and caused a population increase.