FLYING?  Airports serving Baltimore, Washington DC and Philadelphia: 

Baltimore / Washington International Thurgood Marshall Airport (BWI)
Approximate Drive Time to Baltimore Convention Center - 12 mins.
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Web Site: www.bwiairport.com
BWI Marshall is Maryland's modern, user-friendly airport with more than 600 daily domestic and international flights serving more than 65 cities nonstop.

Washington Dulles International Airport (IAD)
Approximate Drive Time to Baltimore Convention Center - 1 hour 8 mins.
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Website: http://www.metwashairports.com/dulles/dulles.htm
Washington Dulles International Airport (IAD) is located in Chantilly, VA on 12,000 acres of land 26 miles from downtown Washington, DC.  It serves 83 domestic destinations non-stop and 43 international each day.

Ronald Reagan Washington National Airport
Approximate Drive Time to Baltimore Convention Center - 54 mins.
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Website: http://www.metwashairports.com/reagan/reagan.htm
Ronald Reagan Washington National Airport (DCA) is located in Arlington, VA just across the Potomac River from the Nation’s Capital.