Originally part of the offices of the president on the White House's second floor, this room was used by several presidents as an audience or waiting room.
It was partitioned near the windows to allow Abraham Lincoln to pass from the Library (Yellow Oval Room) to his office in today's Lincoln Bedroom without encountering anyone. The room has been a Cabinet meeting room since Andrew Johnson.
When James Garfield was shot, it was turned into a kind of ice-house, where various crude air-conditioning machines were installed in an attempt to make the president more comfortable.
William McKinley presided over the signing of the peace treaty with Spain in this room in 1898, which ended the Spanish-American War. The artist Theobald Chartran was inspired by that event to paint a depiction of it, which today hangs in the very room itself.