 Manhattan Construction Company was responsible for the build-out including, installation of electrical, mechanical and plumbing systems, coordination with existing Capitol building systems where the center connects within the Capitol building, and completion of the above-ground East Front Plaza, with related site work and security elements.The space is mainly designed for use as a holding zone for visitors waiting to take tours of the Capitol.The number of annual visitors to the Capitol has tripled from 1,000,000 in 1970 to nearly 3,000,000 as of recent times, and it has become difficult to deal with the congestion caused by such crowds.