The correct answer to this open question is the following.
The Progressive Era represented a time of changes for the American people. From the 1890s to the 1920s, American society witnessed a series of sudden changes basically in politics and economics.
One of the most important reformers of the time was a lady called Jane Addams. Jane loved to help people in need and she decided to found a house to help these people. She founded the Hull House in the city of Chicago, Illinois. There, she basically focused on helping immigrants and homeless people. Her work was very important for those difficult times.
The other reformer I would like to refer to is a journalist named Ida Tarbell, a woman committed to her profession as a journalist, dedicated to report corruption issues in the American businesses. She was part of the so-called "muckraker" journalists that investigated complex issues and exposed corrupt acts in companies such as the oil companies. Specifically, Standard Oil, owned by John Rockefeller.