State Sen. Anthony Hardy Williams is launching a television ad campaign for his Democratic mayoral bid Tuesday, becoming the first candidate to finance such an effort this primary season.

While his campaign declined to say what stations would air the ad or how frequently, a Williams campaign strategist, speaking on condition of anonymity, said the buy was "significant" and signaled the beginning of the on-air campaign that would continue until Philadelphia's May 19 Democratic primary.

The ad, which seems designed to resonate particularly with African American voters, is actually the second of the season, following one produced two weeks ago by a political action committee that supports mayoral candidate James F. Kenney.

Williams' differs in that it was produced and paid for solely by the candidate's campaign and not by a third-party entity. Like Kenney, Williams also stands to benefit from the advertising support of an outside entity, a political action committee known as American Cities. The three founders of Susquehanna International Group, a Main Line trading firm, gave $250,000 last year to launch American Cities.

Williams' ad is notable in its choice of images and voice-over. While it includes a photo of Williams speaking to a mixed-race crowd of men wearing Teamsters jackets, it is heavy on African American faces and themes. That is not unexpected, given that Williams, who is black, is counting heavily on African American support in the primary.

Dawn Chavous, Williams' campaign manager, dismissed the notion that the ad was aimed at one segment of voters.

"The ad was designed for the entire city," she said. "The biographical information is to introduce the entire city to Tony's family, and that clearly is a black family. We wanted people to know what he has done regarding the biggest issues facing our city - education and public safety. We feel the ad accomplishes that."

Produced by Siegel Strategies, a New York-based political-ad maker, the message opens with a snapshot of Williams' grandfather, followed by photos of his father, the late State Sen. Hardy Williams, who ran for mayor in 1971.

"Maybe it comes from his grandfather, one of the first black mailmen on the Main Line," an announcer intones. "Or his dad, Hardy, who was told an African American could not run for mayor and said, 'Why not?' Anthony Hardy Williams has always believed you can find common ground with common cause."

The ad references the impact of various votes Williams took as a legislator to fund Philadelphia public schools and address violence in the city: "He got over a quarter-billion dollars out of Harrisburg to keep public schools open, and stared down the barrel of the gun lobby to take illegal guns off the street."

The reference to school funding is accompanied by a photo of a young African American girl staring at the camera through a chain-link fence. Williams' fight against guns was illustrated by an African American woman holding a child.

It's not that other ethnic groups are excluded from the ad: Williams is seen sharing a steak sandwich with a construction worker who appears to be Latino, and chatting with a white waitress in a diner.

The ad ends with his campaign's stated theme.

"There are over one million people in Philadelphia," the announcer says, "but he is running to be mayor of one city."