Final answer:
During the Progressive Era, reformers like Teddy Roosevelt, Robert M. La Follette, and Samuel J. Tilden fought for diverse causes such as antitrust actions, democratic reforms, and anti-corruption, while William Tweed exemplified the corruption they opposed.
Step-by-step explanation:
Three prominent reformers during the Progressive Era include Teddy Roosevelt, known as a 'trust buster' for his rigorous enforcement of antitrust laws through lawsuits against monopolistic companies; Robert M. La Follette, or 'Fighting Bob', who was a key figure in pushing for democratic reforms and curbing the power of special interests; and Samuel J. Tilden, who fought against political corruption, including leading the prosecution against William Tweed of Tammany Hall. Conversely, William Tweed serves as an example of a corrupt figure from this era, known for his leadership of the corrupt Tammany Hall political machine in New York City. These individuals and their actions exemplify the varied movements to address issues such as corruption, the democratic process, and industrial working conditions, and the different approaches taken by members of the Progressive movement.