CN Tower
"Guinness World Records" has called the CN Tower "the world's tallest self-supporting tower" and "the world's tallest free-standing tower". Although Guinness did list this description of the CN Tower under the heading "tallest building" at least once, it has also listed it under "tallest tower", omitting it from its list of "tallest buildings." In 1996, Guinness changed the tower's classification to "World's Tallest Building and Freestanding Structure". Emporis and the Council on Tall Buildings and Urban Habitat both listed the CN Tower as the world's tallest free-standing structure on land, and specifically state that the CN Tower is not a true building, thereby awarding the title of world's tallest building to Taipei 101, which is shorter than the CN Tower. The issue of what was tallest became moot when Burj Khalifa, then under construction, exceeded the height of the CN Tower in 2007 (see below).
Woolworth Building
The building opened on April 24, 1913. Woolworth held a grand dinner for over 900 guests, and at exactly 7:30 p.m. EST, President Woodrow Wilson pushed a button in Washington, D.C., to officially turn on the building's lights. Attendants included Francis Hopkinson Smith, who served as toastmaster, author William Winter, and businessman Patrick Francis Murphy. On completion, the Woolworth Building topped the record set by the Metropolitan Life Insurance Company Tower as the world's tallest building, a distinction it held until 1930.