CHICAGO (CBS) — A secret lies inside a wood frame home on the northwest side dates back to 1856.

A hidden room in the basement of the Gray-Cloud House fueled speculation it was part of the Underground Railroad to help slaves escape in the mid-19th century.

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Outside the Irving Park home, archaeologists went digging, sifting, and hunting for clues about life at the home decades ago.

“It’s a house that has neighborhood lore that’s somehow associated with the Underground Railroad,” said Archaeology Professor Rebecca Graff of Lake Forest College.

Graff lead the team of students and volunteers. While they didn’t find any obvious proof of the Underground Railroad, she says the dig is a success.

“Put it all together and get a picture of society,” she said. “That was a bucket list for me.”

Graff was excited about a frozen charlotte doll her team found, which likely dates back to the 1800s.

“This is a child’s mug, probably humpty dumpty,” she said pointing to their findings. “This is some sort of mammal bone, this is someone’s meal.”

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“We’re looking for past evidence of people living here and what they left behind,” said Linnea Eich, a student at Hinsdale High School. “I’ve always been fascinated by how people used to live.”

Former Cook County Sheriff, John Gray, built the home in 1856. He strongly opposed slavery, leading to speculation he used his home to harbor escaped slaves.

“To substantiate the Underground Railroad is difficult, because it was secret and clandestine,” said David Cloud, who owns the home with his wife.

“The notion was this was the origin point, one end of the tunnel,” he said, referring to the secret room in the basement.

Cloud said he is bittersweet about the end of the project.

“The dust will literally and metaphorically settle,” said Cloud.

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It is still unclear if the Underground Railroad operated out of the home. The whole operation was so secret that any evidence it existed could have been removed.