Lewis Pinkney, third from right and standing on a barrel in 1906, was a master stonemason who moved north with George and Harriet Stevens and helped build Rushford’s Lutheran Church. (The Minnesota Star Tribune)

For Laura Deering, one of the "aha" moments of her historical research came while scanning the 1905 census for her southeastern Minnesota hometown of Rushford.

Line 18 of that census roll lists Harriet Stevens, a 74-year-old Civil War nurse and widow of town founder, mayor, banker and Union Army quartermaster George G. Stevens. Two lines above Harriet's name, Deering found stonemason Lewis Pinkney — the only name with a "B" for black in the race column otherwise stacked with Ws among Rushford's 1,000 residents in the early-1900s.

"To be honest, I always thought he lived with the Stevenses," Deering said. "So it was a wonderful moment when the census showed it."

It was among key clues in a puzzle Deering has carefully pieced together — showing how this diverse trio came together to literally help build Rushford, today a town of 1,700 people between Rochester and La Crosse, Wis.

Born in Florida after the Civil War, possibly to former slaves, Pinkney became a master stonemason who helped construct Rushford's Lutheran and Episcopal churches, a former high school and a rectory house between 1899 and 1906.

Deering, an information technology worker at the Mayo Clinic, unearthed a photo showing Pinkney standing on a barrel atop the half-built Lutheran Church in 1906. She also found his name etched in the cornerstone of the Episcopal rectory. An architectural book on Rushford's limestone buildings, where Pinkney's name is briefly noted, piqued her curiosity.

But what was a black man from Florida doing in a white town like Rushford more than a century ago? Deering says the answer starts with the town's connection to the Underground Railroad that helped escaping slaves find safe passage as they fled north up the Mississippi River valley in the 19th century.

The Stevenses' progressive, anti-slavery views — and their winter-home work helping African-Americans near Jacksonville, Fla. — might also explain how Pinkney landed in Rushford.

"Scattered over this wide country are to be found hundreds of people who have reason to bless Mrs. Stevens for her work," according to a 1912 history of Fillmore County.

The book says "her good work will never be known in full extent" because she often performed her "good deeds in secret."

Researching the Stevenses' role in the Underground Railroad proved tricky, Deering said, because aiding escaped slaves was illegal — "so … there wasn't a lot of information recorded or written down."

But decades after slavery was abolished, 1880s census logs show both the Stevenses and a child-aged Pinkney all living in Jacksonville — 20 years before they show up at the same address in Rushford.

"To me, the real hero is Harriet," Deering said.

Born in Ohio on July 4, 1830, Harriet Rees Colfax was living in Michigan City, Ind., when her first husband — editor of an anti-slavery newspaper — died at 26.

She volunteered as a Civil War nurse in St. Louis and on hospital steamboats for more than two years.

"Industrious, indefatigable, attentive, kind and sympathizing," one doctor said, "no female nurse … was more universally beloved and respected."

George Stevens was born Dec. 31, 1818, in Oswego, N.Y., but also spent time in Michigan City, where he might have met Harriet. He, too, was a widow — his first wife died in 1863 after they had three children.

Stevens was in his 40s when the Civil War erupted. He signed up despite his age, serving as a quartermaster who provided supplies to the troops. He married Harriet in 1867.

By then, he'd called Rushford home for more than a decade, helping lay out the town and its financial beginnings. "A banker of broad views," the 1912 Fillmore County history book said, "… he was a noteworthy character, a noble soul, and a true heart. His worth will be blazoned widely, whenever the story of the county is told."

Deering said she struck research gold 1,400 miles south of Rushford. She learned the Stevenses were early snowbirds, purchasing property on a creek east of Jacksonville, Fla., in 1879. She found accounts of them using their Florida house as a church school — teaching African-American children and adults to read the Bible. They helped build two Florida churches with people of color filling the pews.

"After the Civil War," Deering said, Harriet Stevens was "in the Deep South doing these things for the black community."

Deering regularly delivers talks on how the Stevenses helped establish Pinkney in the stonemason trade, bringing him to Minnesota where their braided lives stand behind some of Rushford's important buildings.

Deering lives in an 1858 house Stevens built on Rushford's Stevens Avenue — named after George. She's investigating what might be a secret room in her basement — possibly used to harbor runaway slaves.

Her research was derailed when she fell on her icy driveway four years ago, suffering a serious concussion and fractures to her skull, face and wrist. That curtailed the presentations she regularly gave at work, but once she began piecing together the story of Pinkney and the Stevenses, she started giving talks again.

"I felt the story was bigger than my injuries or lack of confidence," she said. "I guess one can say the story keeps on giving."

Curt Brown's tales about Minnesota's history appear each Sunday. Readers can send him ideas and suggestions at mnhistory@startribune.com. His new book looks at 1918 Minnesota, when flu, war and fires converged: tinyurl.com/MN1918.