It was a toilet that witnessed the birth of America: a humble pit latrine, or privy pit, dug deep into the ground behind a small Philadelphia house in the late 18th century.

Latrines don't generally stir excitement, but archaeologists were thrilled to find the brick-lined circular shaft while excavating a site at the corner of South Third and Chestnut Streets in the summer of 2014.

Privy pits are an unusual treasure trove for archaeologists. Along with their primary purpose, they often served as mini-garbage dumps in urban areas before community trash collection was developed.

And the garbage from this privy pit, dug in 1776 (the year that American colonists declared their independence from Britain) and filled in 1786 (the year before the Constitution was written) provides a unique snapshot of life in the first tumultuous years of the United States.

The Cosmopolitan Discards of a Growing City

The contents of this privy, and 11 others found on the future site of the Museum of the American Revolution, are detailed in a recent report by the Commonwealth Heritage Group, which was contracted to excavate the site before the museum's construction.

View Images The Humphreys' Revolutionary War-era privy pit (right), was dug in 1776 and filled in 1786. Archaeologists excavated 12 brick-lined privy pits on the Philadelphia site, which contained tens of thousands of artifacts from daily life in the city. Photograph courtesy Museum of the American Revolution

The earliest pits located by the archaeologists are dated to the first decades of the 18th century, just as Philadelphia was growing as a major trading and manufacturing hub of colonial America.

Ships arriving at the city's busy harbor brought goods from around the world. When German tankards were broken and fine Chinese porcelain dropped on the floor, they were tossed into the privies for archaeologists to recover centuries later.

Researchers then cross-examined the artifacts with information cobbled from sources such as historic deeds, insurance maps, and Quaker meeting notes.

This is how they learned that the privy pit prosaically labeled by archaeologists as Feature 16 was most likely dug around the time that Benjamin and Mary Humphreys bought a house at 30 Carter's Alley on July 10, 1776—two days after the Declaration of Independence was read aloud in a public square just a few blocks away.

The Illegal Revolution-Era Tavern Revealed

The contents of the Humphrey's privy stumped archaeologists. Instead of standard colonial household garbage—broken tea sets, kitchenware, wig rollers—they were finding dozens and dozens of drinking glasses and tankards, several punch bowls, serving dishes, broken smoking pipes, and nearly a hundred bottles that once contained beer, wine, or hard alcohol. They had the rubbish of a tavern, but there was no tavern license issued for 30 Carter's Alley.

There was, however, a record of the arrest of Mary Humphreys in July 1783 for running a "disorderly house"—essentially, an illegal tavern that often included prostitutes among its clientele.

View Images A windowpane from the tavern was etched with a quote from Cato, a play popular with independence-minded colonists, including George Washington, who had it performed at Valley Forge during the war. Photograph courtesy Museum of the American Revolution

Taverns were a social center of colonial life and often the venue for heated political discussions, and the politics of the day were literally etched into the Humphreys' speakeasy.

One of the 619 artifacts recovered from the Humphreys' privy was a fragile shard of window glass etched with the word "love."

"When we first saw that word we thought, 'Oh, it's just some lovesick guy who's drinking too much and writing a message on the window,'" recalls Rebecca Yamin, the excavation's principal archaeologist.

But then more fragments of the windowpane were recovered from the privy, and researchers were able to piece together the phrase "We admire riches and are in love with …"

"And we know the last word is idleness," explains Yamin. Instead of the graffiti of a lovelorn drunk, the archaeologists had recovered a quote from the ancient Roman senator Cato the Younger, featured in an 18th-century play depicting Cato's resistance to the tyranny of Julius Caesar. The play had become popular among American colonists seeking independence from Britain, and George Washington even had it performed for his troops during their difficult winter in Valley Forge in 1777.

"This quote would have been known to people who were thinking politically in 18th-century Philadelphia," says Yamin. "This man was writing a political message, which is so consistent with what we know was going on in the taverns at the time."

From Privy to Public Display

Another political statement from the Humphreys' illegal tavern may have come in the form of a punchbowl recovered from the privy. The glazed bowl depicts a two-masted ship flying the British flag with the phrase "Success to the Triphena." Such punchbowls were made to commemorate a vessel's launch or mark a particular voyage.

Research revealed that a vessel called the Tryphena regularly sailed between Philadelphia and Liverpool, and a newspaper advertisement appeared in the Pennsylvania Gazette on November 28, 1765, announcing that the Tryphena would carry a message from Philadelphia's merchants to their colleagues in Great Britian, asking them to put pressure on the British parliament to repeal the Stamp Act. The act, passed in March of that year, enforced a tax to pay for British troops and was loathed by independence-minded colonists.

View Images A German tankard recovered from a privy highlights the cosmopolitan tastes of American colonists, as well as their love of beer. Photograph courtesy Museum of the American Revolution

While it's impossible to say whether the punchbowl was a reflection of the Humphreys' political sensibilities, it was obviously important enough to be repaired after it was broken during some point in its use.

"It's amazing that an artifact like this came out of the site where they're building a museum about the American Revolution," exclaims Yamin.

In fact, several of the artifacts recovered from the Humphreys' privy will be on display when the museum opens in April 2017, including the "Success to the Triphena" punchbowl.

"Often in urban sites we dig this stuff up and it just goes into the basement of some state institution, never to be seen again," says Yamin, "but in this case it's really going to be seen. We're really excited about that."