Bette Thompson in 2005. (Kevin Clark/The Washington Post)

Bette Thompson, an activist who helped transform the historically black Montgomery County enclave of Scotland, Md., from squalor and near-condemnation into a comfortable community for low- and moderate-income families, died Feb. 3 at her home there. She was 80.

The cause was congestive heart failure, said a son, Leo Thompson.

Scotland was founded in 1880 by Mrs. Thompson’s forebear William Dove, a freed slave who had purchased 36 acres of land at an auction for $210. The area was then known as Snakes Den for its rocky terrain.

The acreage grew slightly over the next decades as other former slaves bought surrounding land and formed a tightknit community between Rockville and Potomac near Seven Locks Road and Tuckerman Lane.

By the 1920s, Snakes Den adopted the more inviting name Scotland. Many such “kinship communities,” as they are sometimes called, dot the region, including Lincoln Park, Sugarland and Ken-Gar. Families stayed in those neighborhoods for generations when segregation was prevalent.

Even after racial discrimination was outlawed, modernity remained elusive: no paved roads, no sewers or water lines, and homes so dilapidated that residents could not obtain zoning permits to make upgrades.

In the 1960s, the development of neighboring areas into ­middle- and upper-class subdivisions began, and Scotland’s 45 families — with a median income of $85 a week, according to a contemporaneous account in The Washington Post — faced pressure to give up their modest property, often ramshackle houses of tar paper and tin.

“Many citizens had no heat or running water — just coal, kerosene, and wood stoves,” Mrs. Thompson told Bethesda Magazine in 2009. “We’d have to bring water back in buckets. . . . Most families had outhouses.”

Montgomery County saw an opening to clear out Scotland, whose property was worth $10,000 an acre to developers, who began applying their influence to move along plans to condemn and annex the property for stables at nearby Cabin John Regional Park.

“They were land-rich and ­money-poor,” the Rev. James G. Macdonell, a retired pastor at St. Mark Presbyterian Church in Rockville, told The Post in 2005. “They were told they could get jobs mucking them out. It was unbelievable and totally insulting.”

“We pride ourselves as being a liberal county, but it was so insensitive,” added Macdonell, who was involved in the effort to help the community. “This was not urban renewal. It was urban removal. This community almost went down the drain.”

Some residents, backed into a financial corner, left Scotland and moved on. In 1965, many white and black residents formed a group, Save Our Scotland, or “S.O.S.,” of which Mrs. Thompson was a founding member and eventual president.

Early efforts were as rudimentary as installing Scotland’s first sewer line and removing some 200 old cars and trash from properties. According to a profile of Scotland by the Washington public radio station WAMU-FM (88.5), the residents became flush with cash after selling all but a dozen or so acres to the county’s park and planning commission.

They fought successfully for zoning rights to delay the planned condemnation and petitioned the federal Department of Housing and Urban Development to build 100 homes — about 75 to rent and the rest for sale. In all, the project cost about $1.5 million, according to a Post account at the time.

Mrs. Thompson, who bought a home, worked at every level of the revitalization movement that brought heating, electricity and water to the new residences. A day-care and community center, among other accommodations, also arrived in time.

Mrs. Thompson later served as the Scotland Civic Association president until her retirement in 2010. “She was a force for change,” said Cynthia Marshall, an organizer with a coalition called Action in Montgomery. “She was someone who could unite 100 people with a single phone call.”

Bette Carol Dove was born in the Scotland community Oct. 19, 1935. She graduated from the old segregated Lincoln High School in Rockville.

In 1957, she married Paul Thompson, who descended from another longtime Scotland family. He was an operations manager at what was then Chesapeake & Potomac phone company and died in 2012. Their son Benjamin Boyd died in 2010.

Survivors include six children, Paul Thompson Jr. of Woodstock, Md., Leo Thompson of Silver Spring, Md., Janet Ross of Germantown, Md., Everett Thompson of Urbana, Md., Patricia Thompson of Bowie Md., and James McClain of Washington; four siblings; and nine grandchildren.

In 2014, a new community center opened in Scotland, complete with sports courts, a computer center and space for events and classes. The center was named in Mrs. Thompson’s honor.

Mrs. Thompson said her biggest reward was seeing the community around her flourish.

“I’m not the type of person that goes around telling people what I do,” Mrs. Thompson told the Maryland Gazette. ‘‘I’m proud of where I live.”