In this photo from June 1920, President Woodrow Wilson signs a bill into law. The lady next to him is Edith Bolling Galt Wilson, the First Lady. She is steadying the paper he's signing to conceal the paralysis he was still suffering from a series of strokes the preceding November. Many historians believe Mrs. Wilson was the defacto President of the United States for much of the last year of her husband's term.
(Woodrow Wilson's first posed photograph after his stroke. He was paralyzed on his left side, so Edith holds a document steady while he signs. June 1920.)