Long & Foster, one of the largest privately held companies in the Washington, D.C. region, was acquired Thursday by HomeServices of America. Terms of the deal were not disclosed."This is big," David Charron, chief strategy officer of Bright MLS, a multiple listing service told The Washington Post. "This is yet another data point that suggests that real estate drives the economy.Long & Foster was founded in 1968 by Wes Foster and Henry Long. Foster, 84, bought out Long in 1979. It's now one of the biggest residential real estate companies in the country by sales volume.Long & Foster has about 11,000 agents in more than 230 offices in the Mid-Atlantic, including Virginia, Maryland, Washington, D.C., West Virginia, North Carolina, Pennsylvania, Delaware and New Jersey.HomeServices of America, Inc., a Berkshire Hathaway affiliate, announced the deal, and said the acquisition includes Long & Foster's business lines in mortgage, settlement services, insurance and property management.The Berkshire Hathaway subsidiary has been aggressively acquiring real estate companies. The acquisition expands HomeServices presence in the Mid-Atlantic. Warren Buffett is the CEO of Berkshire Hathaway.The Washington Post reports.