Mayor Gavin Newsom Wednesday unveiled the first of 73 plaques that will be placed on historic buildings in the Uptown Tenderloin Historic District, including the Ambassador Hotel, where Wednesday's ceremony took place.
Advocates say it will give the blighted neighborhood defined boundaries and a positive identity.
"I thought we need a way where people walking into the neighborhood see this history and we decided, 'Hey, why don't we try to do plaques,'" Randy Shaw of the Tenderloin Housing Clinic said.
The Uptown Tenderloin Historic District was added to the National Register of Historic Places last year.
To encourage upgrades, property owners receive a 40 percent tax credit for renovating historic buildings.