Final answer:
African Americans in Indiana had their right to vote prohibited in 1920 by implementing discriminatory practices such as literacy tests and poll taxes.
Step-by-step explanation:
The right that was prohibited from African Americans in Indiana was their right to vote. This occurred in the year 1920 when the state passed a law that effectively disenfranchised African Americans by implementing literacy tests, poll taxes, and other discriminatory practices.
During this time, many states in the South were enacting similar measures to suppress the voting rights of African Americans, known as Jim Crow laws. These laws aimed to maintain white supremacy and prevent African Americans from participating in the political process.
The 1920 law in Indiana remained in effect until the passage of the Voting Rights Act in 1965, which protected the voting rights of all citizens regardless of race.