These sites were cited in "Washington Underground," a booklet prepared by local archaeology experts, as yielding particularly significant finds in downtown Washington.

l. Convention Center at Mount Vernon Square. Traces of rowhouses purchased in 1849 by the Smith Harley and George Garrison families were found. They were two of a small number of free black families that managed to buy property before the Civil War.

2. Old Civic Center at Ninth and H streets NW. Refuse tossed in a nearby backyard contained more than 70 apothecary bottles.

3. Butt-Burnett Pottery, Eighth and I streets NW. Thousands of pieces of Burnett pottery were found in a "waster pit" where the potter had discarded unusable items.

4. Essex Court, Sixth and I streets NW. New residents who poured into Washington after the Civil War lived in crowded conditions here.

5. Square 530, between Third and Fourth and F and G streets NW. The Richard Burr family's well-tended yard had to be covered with three to six feet of landfill to prevent flooding.

6. MCI Center, between Sixth and Seventh and F and G streets NW. More than 80,000 pieces of household trash were found along with three cisterns and two wells.

7. Block Corner, Ninth and E streets NW. This corner went from the site of a brick home to a post office, to a boarding house to retail shops to a vaudeville house to an adult theater that closed in 1987.

8. Petersen House, 516 10th Street NW. This home, built in 1849 by a German immigrant tailor, was the building to which President Abraham Lincoln was carried after he was shot at Ford's Theatre across the street.

9. Slate Alley, between 12th and 13th and E and F streets NW. This alley was the home of residents who dealt in the junk trade between 1825 and 1855. They buried 544 bottles, plus hardware, window glass, bricks nails and bone in a pit.

10. Federal Triangle, Pennsylvania and Constitution Avenues at Sixth Street NW. Family houses and brothels once coexisted here along a canal that resembled an open sewer and became Constitution Avenue.