The Declaration of Independence, Abraham Lincoln famously said in 1861, "gave promise that in due time the weights should be lifted from the shoulders of all men, and that all should have an equal chance."
Lincoln's speech at Independence Hall provides the title of the latest episode of Philadelphia: The Great Experiment, a 14-part documentary series produced by entrepreneur and politician Sam Katz's History Making Productions.
"We are not in the Civil War battle-wise, but we look at the machinery that made it possible to fight the Civil War," Katz said about the episode, "An Equal Chance: 1855-1871." That technology includes the founding of the Pennsylvania Railroad, advances in medical care, the abolitionist movement, and the Underground Railroad.
Most fascinating perhaps is the story of the city's political conflicts as they played out through two dominant figures from the same Moyamensing neighborhood: Irish American Democratic ward boss William McMullen and African American educator and activist Octavius Catto.
"These two opposing political figures served constituents who were in need and who felt they were shut out of the political process," series director Andrew Ferrett said.
McMullen spoke to Irish immigrants' aspirations to gain a foothold in the city, and Catto fought for a more basic desire: restoration of voting rights for African Americans.
The two men opposed each other during and after the Civil War but set aside their differences - to a point - in their support of Lincoln and the Union.
The episode covers a wide range of key figures, including William Still, one of the organizers of the Underground Railroad. Still's stop was the first for escaped slaves once they were out of the South.
Still not only guided the escapees, he also preserved their stories, said Naomi Nelson, one of the experts in the documentary.
"His job wasn't just to chronicle these stories . . . but also to [establish] whether the stories were true or not," said Nelson, executive director of the Underground Railroad Museum at Belmont Mansion.
Early feminist heroines such as Anne Broomall - a 16-year-old student who defied convention by enrolling in medical school and pursuing a career as a surgeon - and Caroline LeCount - who protested the refusal of streetcar companies to accept black passengers by organizing ride-ins - are also included.
Katz said the concept that ties the episode's many personal stories together is the aspiration to freedom and equality.
"All these aspirational stories . . . are going on while in the foreground there's the Civil War, which had badly divided the city, whose economy was very much dependent on a slave labor force," he said. "It's a cauldron."