The Oval Office is the office of the President of the United States. It is located in the West Wing of the White House. It was established by President William Howard Taft in 1909 while expanding President Theodore Roosevelt's original "temporary" structure of 1902. In 1933, President Franklin D. Roosevelt further expanded the West Wing and moved the Oval Office to the southeast corner. The office measures 34 feet by 27 feet. It was rebuilt by President Herbert Hoover after the West Wing caught fire in 1929.
The White House Museum: Oval Office History