Editing Federal Triangle (section)

===1929–1931===
[[File:FederalTriangle 1851.jpg|thumb|Map of [[Washington, D.C.]], published in 1851 but still extant as of 1926, showing the area around Federal Triangle as originally planned and built in accordance with the [[L'Enfant Plan]]]]
Architectural models of the proposed Federal Triangle development were unveiled in late April 1929.<ref name="Beautified">"Beautified Capital Shown By Models." ''New York Times.'' April 28, 1929.</ref> Design work on the Independent Offices, Justice, and Labor buildings also began at that time.<ref name="Beautified" /> After these models were unveiled, however, the Board once more made changes to the Federal Triangle construction plan to reflect the March and April changes made by Hoover and Mellon. Now only seven large structures were planned, and assigned to the following board members for design:<ref name="Cannadine" /><ref name="Worthy" /><ref>The Independent Offices building was now called the Apex Building, the Labor and ICC buildings were now joined by a Departmental Auditorium, and the General Accounting building had been replaced by the Post Office building. The cost of the Departmental Auditorium was estimated at $2 million. See: "Hoover Urges Funds For Six New Buildings." ''Washington Post.'' April 23, 1930.</ref>
:*Apex Building (formerly the Independent Offices building, and now assigned to house the [[United States Coast Guard]]) - Bennett
:*Commerce Department building - Ayers (of the firm [[York and Sawyer]])
:*Internal Revenue Service building - Simon
:*Justice Department building - Medary
:*Labor Department/Interstate Commerce Commission (ICC) building, and Departmental Auditorium - Brown
:*National Archives building - Pope
:*Post Office Department building - Delano

Two major changes to the complex came in early 1930. The Board and other planning groups had long agreed to site the Justice Department building on the block bounded by 7th, 9th, and B Streets NW and Pennsylvania Avenue NW. But this plan changed in March 1930. Architect John Russell Pope made a proposal to have the Justice and Archives switch sites so that the Justice building would have more space.<ref name="Cannadine" /> Although the change would entail major design alterations in both buildings, Secretary Mellon favored the idea.  The Commission on Fine Arts approved the plan,<ref name="Cannadine" /> and Mellon met with the Board of Architectural Consultants in late March 1930 to discuss the idea.<ref>"Mellon to Discuss Changing of Sites." ''Washington Post.'' March 28, 1930.</ref> Although this initial meeting left the issue unresolved,<ref>"Site of New Justice Building Undecided." ''Washington Post.'' March 29, 1930.</ref> the Board later agreed to Mellon's wishes in April and the two buildings switched plots.<ref name="Cannadine" /><ref name="HooverUrges">"Hoover Urges Funds For Six New Buildings." ''Washington Post.'' April 23, 1930.</ref> At the end of April, President Hoover asked Congress to appropriate $10.3 million (the most yet) to build a new Post Office Department building between 12th and 13th Streets NW, from Pennsylvania Avenue NW south to C Street NW.<ref name="HooverUrges" />

Parking and traffic issues proved immensely vexing for the planners of Federal Triangle.<ref name="Whitaker" /> The original [[L'Enfant Plan]] setting out the streets of Washington, D.C., still existed in the Federal Triangle area.<ref name="Worthy" /> Both C Street NW and D Street NW still ran from 15th Street NW to 15th Street NE.  Ohio Avenue NW ran in a northwest–southeast line from the intersection of D and 15th Streets NW to the intersection of B and 12th Streets NW (soon to be renamed as Constitution Avenue NW and 12th Street NW). Louisiana Avenue NW still ran in a southwest–northeast direction from 10th and B Streets NW to 7th and D Streets NW (along what is currently the diagonal portion Indiana Avenue NW). The McMillan Plan was developed before the widespread use of the automobile, and now the Board of Architectural Consultants had to decide how to accommodate the "horseless carriage" while also making Federal Triangle pedestrian-friendly.<ref name="Worthy" /> The Board began studying traffic issues in late 1927.<ref name="FinalIndorsement" /> A major study of parking needs and solutions was conducted in 1931, and traffic and parking patterns assessed again after the Department of Commerce building opened in early 1932.<ref>"Study of Triangle Parking Needs Near." ''Washington Post.'' December 30, 1931.</ref> To achieve some of the traffic and parking goals, the east–west streets and diagonal avenues were eliminated, leaving only the north–south streets through the area, and 12th and 9th Streets NW were submerged in tunnels beneath the National Mall.<ref name="Worthy" /><ref>"State Names For Streets Slated Today." ''Washington Post.'' January 30, 1936.</ref> In the first major change to the Board's "final" plans, the Grand Plaza was abandoned in favor of a parking lot.<ref name="Worthy" /> The Board considered a number of other solutions to the need to accommodate the more than 7,500 cars expected to arrive every day (including an underground bus terminal and underground parking garage under the Grand Plaza), but in the end only approved a small number of underground parking spaces beneath the Apex Building.<ref name="Worthy" /><ref>"Underground Terminal Suggested for Buses." ''Washington Post.'' October 13, 1927; "Groups Study Car Parking In Triangle." ''Washington Post.'' October 24, 1936.</ref>