Determined to see the changes herself, she was soon on a plane from her home in Los Angeles to Nashville. But when she got to Lynchburg, she found no trace of Green. “I went on three tours of the distillery, and nothing, not a mention of him,” she said.

Rather than leave, Ms. Weaver dug in, determined to uncover more about Green and persuade Brown-Forman to follow through on its promise to recognize his role in creating America’s most famous whiskey. She rented a house in downtown Lynchburg, and began contacting Green’s descendants, dozens of whom still live in the area.

Scouring archives in Tennessee, Georgia and Washington, D.C., she created a timeline of Green’s relationship with Daniel, showing how Green had not only taught the whiskey baron how to distill, but had also gone to work for him after the Civil War, becoming what Ms. Weaver believes is the first black master distiller in America. By her count, she has collected 10,000 documents and artifacts related to Daniel and Green, much of which she has agreed to donate to the new National Museum of African American History and Culture in Washington.

Through that research, she also located the farm where the two men began distilling — and bought it, along with a four-acre parcel in the center of town that she intends to turn into a memorial park. She even discovered that Green’s real name was Nathan; Nearest (not Nearis, as has often been reported) was a nickname.

She is writing a book about Green, and last month introduced Uncle Nearest 1856, a whiskey produced on contract by another Tennessee distillery; she says she will apply the bulk of any profits toward her expanding list of Green-related projects.