William Penn might have founded Philadelphia, but it's Benjamin Franklin who gave the city a civic identity, a communal soul, and a future.

In turn, Philadelphia made Benjamin Franklin, transforming him from a 17-year-old runaway indentured servant to a world-renowned innovator, diplomat, and scientist.

His story is told in "Franklin's Spark," the eighth episode of Sam Katz's TV documentary series, Philadelphia: The Great Experiment, which airs 7:30 p.m. Thursday on 6ABC (WPVI-TV).

Franklin "was born in 1706," a voice-over says in the opening seconds, but "his real birth date is 1723, when he came to Philadelphia."

Every American kid learns about Franklin the Founding Father and the ingenious inventor. (He even produced the first tofu in the Western Hemisphere.) But the half-hour documentary, which covers the first half of Franklin's career through the mid-1700s, focuses not on the inventions but on his stunning range of accomplishments as a Philadelphian.

"My real awareness of him as the founder of the functional Philadelphia, as opposed to the Founding Father, was very thin," Katz said Wednesday in a phone interview.

When Franklin moved to the city, it was engulfed in financial and civic chaos after a severe recession. There was no real law and order, nothing to hold the people together as a community. He came here to make his fortune, but by the time he was done, he also had created a web of institutions - a university and a hospital, not to mention America's first volunteer fire company, library, and insurance company - that gave the city stability and unity.

"He really was this self-made man," said Ursinus College historian and series contributor C. Dallett Hemphill, "and became very wealthy and . . . very powerful at a time when other folks who had a non-aristocratic background were beginning to be able to rise in America."

Franklin created the idea of being American, said Steven Conn, professor and director of the public history program at Ohio State University. "Americans in the 18th century are in an identity crisis," Conn said. Immigrants all, they wondered whether they were "still tied to Europe's economy and values or if they are part of something new."

Conn, a West Philadelphia native who specializes in urban history, said Franklin used his rags-to-riches life story "to invent the American story . . . what it means to be American as something distinct."

Yet Franklin insisted that wealth isn't the only measure of true success. Civic responsibility also matters. "He's famous as a laissez-faire capitalist," Conn said, "but he was absolutely committed to the social good."

Franklin's motives weren't entirely selfless. He wanted to be known as the man who made Philadelphia a world-class city, said series co-writer and director Andrew Ferrett. "He thought . . . it could replace London as the capital of the British empire."

Thursday's episode also examines one of Philadelphia's greatest challenges, its eventual decision to move away from slavery.

Franklin had slaves, as did the colony's governor, James Logan. They knew the region's economic viability rested on the use of free labor, said series contributor Karsonya Wise Whitehead of Loyola University Maryland.

"Yet Philadelphia was at the forefront of the move toward abolition," she said. The leaders of the city's Quaker community had become wealthy through the slave trade, but eventually they came to regard it as a great evil. "Once they came to a decision, they stuck to it and never wavered. It resonated throughout the . . . city."


Philadelphia: The Great Experiment

Episode 8, "Franklin's Spark," premieres 7:30 p.m. on 6ABC. Also available at www.historyofphilly.com