Dan Eberly, Jim Lemert and I were at the Rock Creek Park, DC and saw  
the following---mostly in the Maintenance Yard:

Black-throated Green Warbler
Magnolia Warbler
American Redstart 6+
Black-and-White Warbler
Chestnut-sided Warbler 2
Black-throated Blue
Canada Warbler 2
Common Yellowthroat 2
Red-eyed Vireo
Baltimore Oriole 7+
Scarlet Tanager
Veery

Wallace Kornack
Washington DC