The Oval Office has been the main office for the president since President Taft first worked in it about October 1909. After his inauguration President Taft held a competition to select an architect to enlarge and make permanent the West Wing's "temporary" Executive office built during Theodore Roosevelt's first term. Taft ordered a southward extension of the existing structure. The winning architect was Nathan C. Wyeth of Washington, D.C. who designed the wing expansion with a new office for the President. Wyeth modeled the new president's office after the White House's original oval-shaped Blue Room.

Before moving to the president's house in Philadelphia in 1791, George Washington ordered that the straight rear walls of the principal two rooms be rebuilt into a semi-circular form, or bows. In these bowed walls may be found the inspiration for the oval shape of the Blue Room. This distinctive shape apparently had been preferred by Washington to create a suitable space for a formal reception known as a "levee."

The levee, a tradition borrowed from the English court, was a formal occasion to allow men of prominence to meet the president. Replete with formal dress, silver buckles, and powdered hair, the event was a stiff public ceremony almost military in its starkness. Invited guests entered the room and walked over to the president standing before the fireplace and bowed as a presidential aide made a low announcement of their names. The visitor then stepped back to his place. After fifteen minutes the doors were closed and the group would have assembled in a circle. The president would then walk around the circle, addressing each man by his name from memory with some pleasantry or studied remark of congratulation, which might have a political connotation. He bowed, but never shook hands. When he had rounded the circle, the president returned to his place before the mantel and stood until, at a signal from an aide, the guests went to him, one by one, bowed without saying anything, and left the room.

Although the Oval Office was born in the expansion of the "West Wing" in 1909, the room's distinctive shape was inspired by the Blue Room and its form may be traced to a formal social greeting that was meant by President Washington as a symbolic means of dramatizing the office of the Presidency. After he became president, Thomas Jefferson ended the practice of holding levees and replaced this formal ritualized greeting with a simple handshake.