The Architect of the Capitol, Alan M. Hantman, FAIA, was presented with the task of building the visitor center when Congress decided that people need to understand their Capitol more fully and wanted a design with an open floor plan. This design plan includes space for exhibits, food service, two orientation theaters, an auditorium, gift shops, security, a service tunnel for truck loading and deliveries, medical and storage facilities and much-needed space for the House and Senate. Within the design plans to create larger and more efficient interiors is the desire of Congress to create an experience that conveys the historic importance of the country's Capitol.

Annadale's mock-up panel was placed in the Capitol Rotunda Building for viewing and was selected by the Capitol Preservation Commission, which is under the guidance of Hantman and CVC Project Executive Bob Ilixon. Other members of the Commission in the selection process included 17 members in the 108th Congress.

In total, more than 151,000 square feet of raw sandstone slabs with a honed finish will be used for Phase II of the project to produce 45,900 cubic feet of finished material. The typical pieces for the interior wall measure 4 feet, 11 5⁄8 inches x 1 foot, 8 5⁄8 inches x 3 inches.

The massive interior shell will require three years of construction to lay plumbing and electrical lines, and work will also include placement of granite pavers in the plaza. The general contractor for the project is Manhattan Construction Co. of Fairfax, VA, and the installers for the project are Boatman and Magnani, Inc. of Capitol Heights, MD. Work began in April 2003 and is expected to be completed by the spring of 2006.