Discarded columns and stonework are currently stored in a "secret" storage space that is readily accessible in an area of Rock Creek Park (See my other project, "Fragments of the U.S. Capitol").
National Arboretum - Capitol Columns
Twenty-two 34-foot tall sandstone Corinthian columns were removed after expansion of the U.S. Capitol building in the 1950s. The columns were eventually taken out of storage and English landscape architect Russell Page designed a setting for them on a knoll near the main entrance of the National Arboretum.