The historical event that involved the questioning of women's roles in American politics was the women's suffrage movement, particularly culminating in the 19th Amendment's ratification in 1920. This movement mobilized women across the nation to advocate for their right to vote and increased political participation. It challenged traditional gender roles and highlighted the importance of women in shaping societal and political landscapes. The struggle was marked by notable leaders like Susan B. Anthony and Elizabeth Cady Stanton, and it was critical in fostering further advancements in women's rights, laying the groundwork for future activism.