"[6] Dozens of Editors review entries from hundreds of Correspondents before they are accepted into the database.
[7][8] Artist Paul Druecke described the HMdb as "a different sort of catalogue", one that "allows geeks like me to explore historical plaques throughout the United States.
"[9]: 377 Druecke did a series of charcoal drawings depicting official state-sponsored plaques.
[9] In 2011, Silvio Lacetti argued that the HMdb "offers a wonderful opportunity" for history teachers to instill interest in students by being "a Columbus leading his or her young crew on journeys of local historical discovery", enabling them "to search, discover and learn" through historical markers.
[11] The HMdb served as the basis for the database for the online augmented reality game Ingress, which was then later repurposed for Pokémon Go.