The collection consists of 146 salt-paper prints (structural and decorative details) of the United States Capitol Dome, between 1855 and 1862. Dimensions range from 6 ¾" x 9 ½" to 17 1/8" x 10".

For decades, hundreds of stones that were once part of the United States Capitol Building were abandoned behind a maintenance facility off an unmarked trail at a park in Washington, D.C ...