If you can say one thing about New York public officials in the early 1800s, it’s that they knew how to party. The extent of their raucous boozing and debauchery is being carefully catalogued inside the newly opened Nan A Rothschild Research Center, a repository in midtown Manhattan housing over one million archaeological artifacts from New York City’s past.

On a recent Thursday morning, Amanda Sutphin, the director of archaeology for the New York Landmarks Preservation Commission, sorted through some of her favorite City Hall party relics. She picked up a smooth, cylindrical object the size of stubby Cuban cigar. “Take a look at this douche,” said Sutphin, who is tall, with glasses and a short brown bob. “It’s made of cow bone though, so it might have felt a bit rough.”

The park behind City Hall, which was built in 1812, is by far the repository’s largest haul – the city has collected over 400 boxes of artifacts from the site. A lot of them seem to be liquor bottles. “Whenever someone important would come to the city – like, say, Marquis de Lafayette – they would always throw a giant party.” Sutphin paused, still holding the douche. “But I’m not saying this douche was found at Lafayette’s party!”

The cow bone douche. Photograph: Laura Parker

The douche was uncovered in 2011, and caused enough of a stir that it was featured on a Saturday Night Live skit some years ago. “It was just like, ‘They found a douche behind City Hall, ooooo…” A pause. “I never said it was funny.”

Originally, no one could work out what it was – the archaeologist who found it thought it was a pepper grinder. “But you can see here,” – Sutphin unscrewed the top – “it’s got a little plunger. And on the ends you can see the small holes.” It probably belonged to a young woman from the middle class – a more well-to-do society lady would have had a glass douche. “For a smoother experience,” Sutphin said. Some women even used theirs as contraception, although, as Sutphin noted, “Probably wasn’t very effective.”

The repository is a small, climate-controlled room in the basement of a Durst Organization building on West 47th Street. There are about 1,5000 cardboard boxes – “archival boxes” is the technical term – filled with artifacts from 14 sites across the five boroughs, stacked neatly on white shelves. There are a lot of ceramics from the late 18th and early 19th centuries, remnants of the Revolutionary war (bayonets and buttons made by soldiers when it was too cold to go outside), and a lot of evidence of what people used to eat: bones – both cow and dog – and oysters as large as saucepans. This is because New York harbor in the 18th century was home to one of the largest oyster beds in the world; the street carts that now sell hotdogs used to sell oysters in all varieties: raw, pickled, fried. “Having an oyster back then would have been like having a nice steak,” Sutphin said.

Sutphin studied at Barnard College and has been with the Commission for 20 years. Her job is to review development projects happening throughout the city and figure out if there are any potential archaeological treasures to be found. “You need to have a good grasp on the city’s history, particularly things like knowing where the early settlements were, what was farmland and what wasn’t – and most importantly, where people dumped their trash.” The most common archaeological sites in the city are 19th century privies – toilets, in other words. Before New York City had public water, people used outhouses, with a separate cistern to store water. When public water was introduced, people began filling their outhouses with household trash. For Sutphin, colonial lavatories are about as exciting as it gets. “It’s a time capsule of what that period is like. Sometimes you find incredible things: people’s old dishes, their secret liquor stash.”

Sutphin’s job is rare: only a handful of other major US cities have archaeology programs, Boston and DC among them. “A lot of people think it’s like Indiana Jones,” Sutphin said, somewhat annoyed. “It’s not about finding some cool thing from the past that has magic powers – it’s trying to recreate a puzzle of what the past was like.”

Next to the City Hall party items, Sutphin had assembled a selection of the collection’s quirkier items: burned coffee beans – “Coffee was as important in the 19th century as it is now. Everyone drank it because the water was kind of shit back then” – a femur from a passenger pigeon, which once ruled the skies above New York before being hunted into extinction some 100 years ago – “They had bright, pretty feathers so everyone wanted some” – and a tea cup set belonging to the Van Cortlands, a wealthy family from the Bronx. Coincidentally, some of the items in the repository were until very recently stored inside the women’s restroom in Van Cortland park. “I do not know why or how the decision was made to store the collections there – but it was made many years ago and I think clearly shows the need for the repository both as a climate controlled facility and as a place that is managed by people who understand the importance of the collections,” Sutphin said.

The wine jug seal from Benjamin Fletcher. Photograph: New York Landmarks Preservation Commission

The only item in the collection associated with a particular individual is a wine jug seal belonging to Benjamin Fletcher, who was governor of New York from 1692 to 1697. (It was normal for wealthy people to send their own fancy glass jugs to taverns to be filled with wine.) Fletcher was a notorious lover of pirates, to the point where he allowed them safe passage in New York and as a result, was swiftly fired from his post and sent back to London, where he faced charges of conspiracy and bribery. “He was a naughty boy,” Sutphin conceded.

Although the repository is only open to researches and scholars, the Commission recently launched an online digital archive, where anyone can view images of the collection and read up on each artifact’s backstory. Admittedly, these descriptions aren’t very imaginative. “Nuremberg single wire spectacles, small pieces of copper alloy wire tying the circular loops closed, probably Klemmer’s clip, glass lenses missing.” In real life, the spectacles look like they’ve seen better days. Sutphin pulled them out of their box to show me. “I don’t know how effective these would have been – maybe more effective than the douche?”

She started to laugh, but stopped abruptly. “But seriously,” she said, leaning in closer. “The more stories we understand about our city the more people are represented, the richer we all are. It’s very much an anti-Donald Trump view.”