One day while sitting in Independence Square, I watched a group of African American schoolchildren moving briskly through the square.
Unknowingly, they had just hustled by an unmarked spot where Frederick Douglass stood in 1844 to speak against slavery.
Whatever these children learned of American history that day, it did not include the ongoing struggle for freedom that persisted long after the Declaration of Independence and the drafting of the Constitution.
In recent days, it has been heartening to see public attention directed toward the issues of freedom and slavery that existed in Philadelphia during the American Revolution and the early years of the nation.
But if we focus our attention only on slave quarters at the long-demolished Market Street house where George Washington lived, we risk overlooking the long and complex history of African American life in and around Independence Hall.
Washington's slaves were not the only African Americans who inhabited the space we now know as Independence National Historical Park. Archaeological evidence from the northernmost block of Independence Mall proves the presence of African Americans.
Furthermore, the blocks immediately south of Independence Hall developed into one of the largest, most vibrant communities of free black Americans in the young nation, clustered near Mother Bethel A.M.E. Church and St. Thomas African Episcopal Church.
Amid the triumphs of 1776 and 1787 that we associate with Independence Hall, if we listen closely, we can also hear the echoes of slavery. In this building, the Pennsylvania Assembly passed the first state law for the gradual abolition of slavery in 1780, a law so gradual that slaves were legally held in Pennsylvania until the 1840s.
The United States Congress, while meeting in Congress Hall in 1793, passed the nation's first fugitive slave law.
Stunningly, Independence Hall was a site for enforcing the return of fugitives to slavery during the 1850s. ,
In the aftermath of a tough new fugitive slave law passed in 1850, dramas of slavery and freedom played out in the U.S. Marshal's office and U.S. District Court, both housed on the second floor of Independence Hall until 1854.
Slave-catchers from the South captured accused fugitives and took them to the marshal's office, where they were sometimes incarcerated overnight to await hearings to establish their identity.
Abolitionist lawyers scrambled to assemble a defense for the fugitives, who by law were not permitted to testify. Black Philadelphians gathered in Independence Square during the hearings to await the outcomes.
These cases were not numerous. I have documented six such hearings in the second-floor courtroom during 1850 and 1851, and another historian has identified 13 cases in Philadelphia from 1850 to 1860.
But these were highly charged, emotional events in a city divided in its opinions about slavery.
Of the cases in Independence Hall, three accused fugitives were sent back to slavery. In one other case, sympathetic neighbors collected $700 to purchase a fugitive's freedom - a transaction that took place in the U.S. Marshal's office in Independence Hall.
The National Park Service is mindful of this history. How that awareness will translate into public interpretation remains to be seen.
Independence Hall and its adjacent park have long been dedicated to commemorating the ideals of freedom and equality that resonate from the nation's founding documents. To acknowledge that this place is also laced with the issues of slavery does not diminish the symbolic power of the building or its most famous artifact, the Liberty Bell.
Indeed, we can tell a more powerful story of the struggle for freedom in many dimensions, from the colonial era to the present day.