It was during Governor General Francis Burton Harrison's administration (1913-1921) that the beautiful Executive Building was built at the garden east of the Palace to house the offices of the Governor General and Vice Governor on the first floor, and to provide guest rooms for official visitors on the second floor.

The reinforced concrete building, with precast concrete ornaments on its exterior and handcarved panels and intricate mouldings in its interiors, was designed by Ralph Harrington Doane, Consulting Architect at the time. Though little is written about Doane, his other known public buildings, the Pangasinan Provincial Capitol, and the Leyte Provincial Capitol affirm to his refined skills and sophisticated qualities as an architect. Both Capitol buildings, with high ceilings and wide windows, contain spaces highly adaptable to the tropical climate, and designed in classical style similar to those used by architects of Federal buildings and memorials in America at that time.

The architecture of the Executive Building reflects the mixture of American and Fil-Hispanic influence done in elegant manner. In its interior are intricate wood panels and carvings, and coffered ceilings. And in its exterior are ornamental concrete and ironworks, all serving as testaments to the high skills of Filipino craftsmen. The formality of its planning fits to the bureaucratic nature of the government that it once served. As in his two Provincial Capitols he designed, Doane used classical elements in the design of Executive Building like arched windows and doorways, and classical columns for the porticos north and south sides of the building, and facing what was once gardens. Classical elements like what Doane applied were extensively used by American architects of Federal projects at that time, and evident in traditional Spanish architecture as well.

Governor Francis Burton Harrison must have influenced the design of the Executive Building. In his memoirs, his keen observation of Malacañang Palace reflects his profound understanding of architecture and his appreciation to Spanish builders: "Malacañang Palace is one of the most comfortable and delightful homes in the tropics. The Spaniards were the best of all the European races as builders in the hot countries, perhaps because they learned how to build in their own. The English make themselves miserable in the tropics by reproducing in every respect possible the houses and methods of life of their own cold climate. Malacañang was originally purchased by the Spanish government about a century ago as a casita or country house and has been added to from time to time until it has how huge floor spaces of old hand-hewn hardwood, and is admirably fitted for large entertainments. Malacañang has been greatly enlarged and modernized in the last few years and a beautiful executive office building in the garden has just been completed…"

Governor Francis Burton Harrison's term of seven and a half years was the longest of all American Governors, making it possible for the construction of the Executive Building to finish just two months after his term ended in October 1921. He was succeeded by Leonard Wood, the first Governor General to occupy the Executive Building and the last to hold office in the Ayuntamiento in Intramuros. For the next 16 years, five other American Governor Generals held office in the Executive Buildings: General Leonard Wood 1921-1927; Henry L. Stimson 1928-1929; Dwight F. Davis 1929-1932; Theodore Roosevelt Jr. 1932-1933; and Frank Murphy 1933-1935.

Manuel L. Quezon, the first Filipino President under Commonwealth, moved to Malacañang after his being elected to the highest office of the land in 1935. During his term construction and improvements took place. Little is known of the original plan of spaces in the Executive Building as Doane envisioned largely because original drawings were lost and have yet to be recovered for proper preservation of this historic building.

General Douglas MacArthur's assistant, Dwight Eisenhower, held office in Executive Building as liason between the Field Marshal of the Philippine Army and the President of the Commonwealth. Under Quezon, the Council of State Room and an Executive Office were added, where presidents had meetings during all subsequent administrations. The Executive Secretary also held office in this building. In 1972, the Executive Building was cleared of its offices and employees and the entire second floor converted into the large Maharlika Hall for social functions and official gatherings. While Ferdinand Marcos kept the Executive Office for his use, the Council of State Room was merged with the Cabinet Room and turned into a television studio. The ornate rooms on the ground floor were also turned into offices and heavily damaged.

In 1986, Marcos held his final inauguration in this building; after the success of the Edsa People Power Revolution, President Corazon C. Aquino ordered the building renamed Kalayaan Hall, to commemorate the return of democracy and liberty to the Filipino people. With the purchase of the San Miguel property next door, a New Executive Building was built, and Kalayaan Hall turned into press offices, then a museum during the administration of President Fidel V. Ramos. During the Estrada administration it was made strictly a Press Office building, and serves much of that purpose to this day. However, recognizing the historical value of this building, Kalayaan Hall will be used as a museum until the projected rationalization of the Palace can take place. At some future time, this building may once again be used for what it was intended -the offices of the Chief Executive of the land.