Modifications and dates Constructed between 1928 and 1930. In 1942 the ground floor facade and glazing was boarded up with hardboard screens. An air-raid shelter was constructed in the basement around the same time. 1940s became accommodation for a range of Commonwealth Departments, and the United States Armed forces' headquarters in Sydney. Anecdotal evidence links General MacArthur's name with a system of tunnels running beneath York Street to Circular Quay and Victoria Barracks. These were constructed prior to the Second World War and it is likely that at least one of them housed emergency telephone equipment should armed conflict within Sydney damage or destroy existing exchanges. November 1945 compulsorily acquired by the Commonwealth government. May 1946 a special conference held to decide Commonwealth use for the building. Successful applicants for floor space included the Postmaster General's Department, the Repatriation Commission, the War Service Homes Commission, the Film Censorship Board and the Department of Labour and Industry. 1945+: massive intervention in the interior has been conducted since the Second World War resulting in removal and obstruction of much of the original interiors. 1948: telephone exchange opened in December. 1950 the Post Office was opened in December. Heritage listing As at 1 October 1997, The Grace Building is historically significant because of its associations with the retail boom of the 1920s. It epitomises the optimism and dynamism of that period as well as the subsequent economic collapse and Great Depression. It is also associated with the World War II presence of United States military forces in Australia and with General Douglas MacArthur in particular. It is architecturally significant because it is Sydney's finest example of the skyscraper gothic style which illustrates the American influence on Australian commercial architecture and is a distinctive landmark in the city. It was one of the most significant works of Morrow and Gordon, a leading architectural firm of that period. The Grace Building is technically significant because of the unusual reinforced concrete slab and beam construction and the glazed architectural terra cotta cladding. Grace Building, Sydney was listed on the New South Wales State Heritage Register on 2 April 1999 having satisfied the following criteria. The place is important in demonstrating the course, or pattern, of cultural or natural history in New South Wales. The Grace Building is historically significant because of its associations with the retail boom of the 1920s and epitomises the optimism and dynamism