Monorail subway from Capitol to Senate. Construction work
<a rel="nofollow" class="external text" href="http://hdl.loc.gov/loc.pnp/pp.hec">Harris &amp; Ewing, photographer</a>
<a rel="nofollow" class="external text" href="https://www.loc.gov/pictures/item/hec2008001020/">Library of Congress</a>