By 1948, the White House was on the verge of collapse. It would have been cheaper to start from scratch, but Truman new better:
Harry S Truman inherited a White House that was in horrendous shape. After the British nearly burnt it to the ground in 1814, the construction of 20th-century innovations—indoor plumbing, electricity, and heating ducts—had also taken its toll on the structure. The building was nearly 150 years old, and it showed its age. ...
The social events of the 1948 holiday season had to be canceled. And with good reason: Experts called the third floor of the White House “an outstanding example of a firetrap.” The result of a federally commissioned report found the mansion’s plumbing “makeshift and unsanitary,” while “the structural deterioration [was] in ‘appalling degree,’ and threateningcomplete collapse.” The congressional commission on the matter was considering the option of abandoning the structure altogether in favor of a built-from-scratch mansion, but President Truman lobbied for the restoration. ...
So it had to be gutted. Completely. Every piece of the interior, including the walls, had to be removed and put in storage. The outside of the structure—reinforced by new concrete columns—was all that remained. See images of the reconstruction below. (Photos and captions are from the National Archives via the Truman Library.)
