He has worked on national security, counterterrorism and other topics for Tew Cardenas LLP, his resume says, and was a legislative assistant for the American Legislative Exchange Council, a nonprofit organization that supports conservative lawmakers.
For the last year, he's been assistant director of government relations for the Washington, D.C.-based ONE Campaign, which fights poverty and disease, particularly in Africa.
Brennan, a Republican, formed a fundraising committee in January, for no specific office, but didn't file to run until July 1, shortly before deadline.
His Republican opponent, Neil Parrott, announced his candidacy in September 2009.
The primary will be Sept. 14. The winner will face Democrat Brien J. Poffenberger in the Nov. 2 general election.
Brennan said he's behind in campaigning and raising money, but ability and qualifications matter most. He said he doesn't think Parrott would be as "ready to go bare knuckles in Annapolis" as he is.
Both men waited until current delegate Christopher B. Shank decided to run for state Senate before getting in the race.
Brennan said he knows the nuances of political negotiation -- the GOP is greatly outnumbered in the General Assembly -- and won't compromise on principle.
Delegates serve four-year terms and are paid $43,000 per year.
Date of birth: Sept. 15, 1968
Address: 18611 Outpost Road, Keedysville
Education: Bachelor's degree in government and international relations from the University of Notre Dame in 1990
Occupation: Assistant director for government relations for ONE Campaign, which fights poverty and disease, particularly in Africa
Party affiliation: Republican
Political experience: Worked on Capitol Hill for House Committee on International Relations, Senate International Narcotics Control Caucus, and for U.S. Rep. Cass Ballenger, R-N.C.; in Emmitsburg, Md., served one year on town council, was president of planning and zoning commission, served on board of appeals and is chairman of ethics commission