Baltimore is served by three airports
Baltimore/Washington International Thurgood Marshall Airport (BWI) is located 10 miles from the Convention Center between Washington, DC and Baltimore, MD. This is the closest airport to the Conference hotels and Baltimore Convention Center; the airport hosts national as well as international flights.
You can use also one of the two other Washington DC airports:
Reagan National Airport is located 56 miles from the Conference hotels and Baltimore Convention Center in Washington, DC and hosts all major carriers.
Dulles international Airport is located 60 miles from the Conference hotels and Baltimore Convention Center outside of Washington, DC in Dulles, Virginia. This airport hosts both national and international flights, of all major carriers.
Note however that transportation from both of these latter airports to and from Baltimore is expensive.
Baltimore is served by Amtrak Northeast Corridor trains with frequent connections to Boston, New York City, Philadelphia, Washington DC and all the major cities of the Northeast Atlantic sea board.
Link to Visit Baltimore web site http://baltimore.org/transportation/getting-here
Top row photos courtesy of Visit Baltimore