This weekend, the 18th-century door finally creaked open at the place known as Uncle Tom’s Cabin, and the first tour group stepped off the hot Bethesda, Md., sidewalk and into the one room where Josiah Henson lived as a slave.

Inside, tour guide Warren Fleming talked about how Henson’s pre-Civil War book was the basis for Harriet Beecher Stowe’s “Uncle Tom’s Cabin.” Then Fleming told his own story, about how his great-great-grandfather had been enslaved on a Montgomery County, Md., plantation, and how proud he was to guide the first tours inside Henson’s place.

“Uncle Tom is America. This cabin tells us where we were and where we have to go,” said Fleming, 53, a commissioner on Montgomery County’s historic preservation committee. Visitors – there were more than 1,000 – were a mix of races and ages: more old than young, more white than black. Three tours went on simultaneously for 4 1/2 hours as guides worked to get everyone inside the cabin where Henson lived from 1795 to 1830.

The cabin and the attached three-bedroom house always had been privately owned. The 1-acre property was put on the market last year, and the Maryland-National Capital Park and Planning Commission bought it for $1 million. The property will be restored and might be used as a museum or an African American history research center, said Gwen Wright, Montgomery County’s historic preservation supervisor.

The 15-minute tours began inside the 13-by-17-foot cabin with hardwood floors and curtained windows. In Henson’s era, the floors were dirt, the ceiling was lower and the cabin had a sleeping loft. Over the mantle of a stone fireplace is a drawing of Henson and a poster with an excerpt from “The Life of Josiah Henson, Formerly a Slave,” published in 1848. Harriet Beecher Stowe later wrote “Uncle Tom’s Cabin” while living in Brunswick, Maine.