May 11, 2026 – Hartford, Wi – It started like a chapter torn from a dusty Hardy Boys mystery. A forgotten clue. A hidden compartment. Months of dead ends. And finally, buried inside the walls of Hartford City Hall, a copper box untouched since 1930. For Sally Jensen, the adventure began quietly in 2024 while volunteering in the History Room at the Hartford Public Library.

“I was volunteering and working on a history piece on the City Hall building,” said Jensen. “There’s a whole binder of all the downtown buildings. I thought I’d get City Hall done before Police Chief Scott MacFarlan retired.”
Then came the discovery.
“I’m reading through this stuff and I’m like, ‘What? There’s a time capsule in that building? WHHHAATTT? How does nobody know about this?’”

The reference came from old editions of the Hartford Times dating to 1930 and an addition to Hartford City Hall. According to the article, an 8-by-10-inch copper box had been sealed into the cornerstone during a ceremonial event nearly a century ago.
Inside the copper box, according to the newspaper account, were photographs of city officials, copies of newspapers, a 1930 census report, telephone directories, photographs of the old City Hall, organization membership lists, and a written history of Hartford.

According to World Population Review and US Census data, the population of the City of Hartford, WI in 1930 was 3,754.
But first, Jensen needed proof the capsule still existed.
That launched months of detective work worthy of Nancy Drew herself.
Jensen contacted city officials, the police chief, the building department, and concrete specialists. At one point, a concrete scanning company, Con-Cor that was privately hired, examined the building and marked possible locations with bright red X’s.

“They swore it was there,” Jensen said. “But I kept looking at it thinking, ‘I don’t know, man.’ Nobody wanted to damage the stone.”
The trail nearly went cold.
Then Hartford mason Whitey Wagner from Bill Wagner Construction stepped into the mystery.
“Sally said there was a time capsule in there,” Wagner said. “It was pretty neat to have them ask me to look for it.”
Everyone originally believed the box was hidden on the north side of the cornerstone where a smaller section of stone appeared altered.
A second company, Interstate Concrete, marked a different location in white chalk.
“I contacted the mason after the first scan to get a mason’s perspective. That is why we started on the side,” said Jensen. “Then when nothing came up there, I showed them the second scan of the chalk drawing, which prompted them to drill in from the side to look into the front. With the help of Hartford DPW’s camera they located it in the front of the cornerstone under the carved 1930.”
Wagner and his crew carefully removed part of the stone and searched with a camera.
Nothing.
“Disappointed,” Jensen admitted. “Deflated.”
But another clue emerged after additional scanning from Interstate Concrete suggested a void lower in the structure.

Wagner’s son, Logan Wagner, drilled a narrow exploratory hole while workers fed a small camera into the opening.
“He says, ‘I think I went through something,’” Whitey Wagner said. “Then they put the camera down in there and they could see everything. Papers and stuff like that. So then we knew exactly where it was.”

Bingo.
The camera had entered the copper box itself.
“Oh my gosh,” Jensen said. “I was so happy.”
The crew carefully cut into the front face of the massive cornerstone and extracted the copper time capsule that had remained hidden since June 1930.
“It was fun,” Wagner said. “Very exciting.”
His son Logan agreed.
“He said that was such a neat experience to be part of,” Wagner said. “When they put another box in, he wants one of our business cards in there.”
The box itself was not filled with gold coins or buried treasure.
“No doubloons,” Wagner said.
Click HERE for history of Hartford, WI and 1930’s mayor Adam F. Poltl
Instead, the true treasure was history itself.

According to the original 1930 Hartford Times article, the contents include:
- Photographs of Hartford Common Council members
- Directories of city officials
- 1930 newspaper editions
- A telephone directory
- Photos of Old City Hall
- A 1930 census report
- A written history of Hartford
- Mayoral addresses and ceremony records
- Organization membership lists tied to the building project
For Jensen, the experience became something larger than uncovering forgotten documents.
It became proof that local history still has secrets waiting quietly behind old stone walls. “This is such a good signature piece for the opening of Museum 53027,” said Jensen. “I hope they can get it cleaned up and laid out before the ribbon cutting.”
The new Museum 53027 will be open at 57 N. Main St., Suite B. in Hartford, Wi.










