However, when the Progressive Era came, these historical societies finally started being seen as "institutions with a capacity or obligation to serve the public." There started to become significant growth in the public’s interest in local history when the 20th century came around, and this was apparent with the overall concern for historic preservation of cities that were going through architectural and demographic changes.
The transition during the Progressive Era marked a turning point, as historical societies began to be perceived as entities with a duty or obligation to serve the community. This led to an increase in public enthusiasm for local history in the 20th century, which was reflected in the widespread concern for preserving historic cities undergoing transformation.