The Reserve Officers Association Building is located East of the Capitol building and directly South of the Dirksen Senate Office Building at the corner of 1st Street and Constitution Ave NE.
From the Metro:
ROA HQ is approximately a 15 minute walk from two Metro stations.
Union Station (Red line)
Walk South toward the Capitol dome on either 1st Street or Delaware, cross Constitution Ave, and ROA will be on your left.
Capitol South station (Blue or Orange line)
Walk North along 1st Street past the Library of Congress and the Supreme Court, and ROA will be on your right.
There is limited parking around Capitol Hill, but the surrounding neighborhoods do have two hour spaces. The closest parking garage is Union Station.