They might have talked of Mr. Burgow's woodworking in children's toys, or trading, or commonplace events - the equivalent of our ball scores.
What they said isn't known, but recent archaeological finds hint at such ordinary day-to-day interactions.
And that makes for rich irony.
How so? Consider the spot: around Fifth and Market Streets, only a block from where the founding fathers fleshed out the ideals of American independence and freedom.
Those ideals were to go unrealized for most African Americans for a further century, yet here were white and black Philadelphians living "side by side, cheek by jowl," as one National Park Service official put it.
What's that? Oh, so you didn't learn much about the free African American community of old Philadelphia during visits to the Liberty Bell?
Well, that needs to change. In fact, it is changing - if slowly, thanks to archaeological finds as well as spirited critiques of history-as-usual by historians and civic leaders.
Credit the makeover of Independence Mall, with its new Liberty Bell pavilion, Independence Visitor Center and the National Constitution Center. All that digging has unearthed more than a million artifacts.
A rich portrait of 18th-century life waits to be told in those artifacts. It's not just a story of the powdered-wig crowd, but of a thriving community where free black leaders formed early independent black institutions and agitated for slaves' liberation.
Detective work by local historian Edward Lawler Jr. has revealed the footprint of President Washington's house at Sixth and Market Streets - and placed the President's slave quarters on the bell pavilion's threshold.
Now the challenge is to weave more of that buried past into the story told to Independence National Historical Park visitors, including a renewed look at the nation's slave-owning founders.
The outcry for this more realistic telling of the past is the right thing to do on moral grounds. But it's also an unprecedented opportunity to enhance tourism by giving a fuller picture of history. What could be better?
Given the city's recent success in attracting African American visitors at three times the national average, just imagine the appeal. As Harry Harrison, head of the African American Museum in Philadelphia, notes, "The depth of Philadelphia history is deeper than anybody imagined."
The first glimpse of that depth will be when the Liberty Bell pavilion opens next year at Sixth and Chestnut Streets, and the Park Service unveils an impressively reworked exhibit.
No longer just noted in passing, the bell's anti-slavery link as a symbol adopted by 19th-century abolitionists will be explored in detail. Other displays will focus on the irony that the dream of liberty was not realized for decades for African Americans.
The Park Service consulted a distinguished group of local and national historians, from Temple University's Charles Blockson to the Smithsonian Institution's Fath Davis Ruffins.
Now Park Service officials need to move beyond the Liberty Bell, drawing on partnerships with historians and developing new alliances with institutions such as the African American Museum.
Discoveries made at the National Constitution Center site could form the basis for a stand-alone exhibition on the free-born African American community. With the homes of several dozen individuals excavated, a wealth of information is known.
More might be learned at a planned bus depot on a site where James Oronoke Dexter, a founder of the first black church, lived. Unearthing that knowledge would require funding. A first step would be to determine whether a pre-1958 building at the site disrupted all remnants of the colonial era. That seems quite possible.
Excavate or not, it's imperative to commemorate. "We the people" will echo across Independence Mall when the Constitution Center and the dazzling Liberty Bell pavilion open next year. But the experience for visitors to the city's historic district will be that much more rich if the story told includes all the people.