The columns were first built for the East Portico of the Capitol in 1828. They were quarried from sandstone and were barged to Washington, before the familiar Capitol dome was completed. Their stay at the Capitol was to be limited by an oversight. The dome of the Capitol, completed in 1864, appeared as if it was not adequately supported by the columns because the iron dome that was ultimately built was significantly larger than the dome that the designer envisioned. So, now the columns sit at the National Arboretum in Washington, DC.