Until the arrival of Malaysia's Petronas Towers in 1998, Sears Tower in Chicago had held the record as the world's tallest building for 25 years.
The Sears Tower is a familiar sight on the Chicago skyline
It still retains that record when measured to the tip of its antennas, and remains the tallest building in the US and a dominating sight on the Chicago skyline.
The skyscraper was originally commissioned by Sears, Roebuck and Co, which was the world's largest retailer at the time. The firm had 350,000 staff and wanted a suitable headquarters.
The architects Skidmore, Owings and Merrill devised a specific support structure for such a large building - square tubes of welded steel with floors suspended within the tubes.
Work began in 1970 on the site at Wacker Drive. It took three years to complete, at a cost of $175m (£96m) at the time.
The finished building measures 442m (1,450ft) - 526m (1,725ft) to the tips of the antennas. It has 110 floors with a total enclosed area of about 424,000 square metres (4.56m sq ft) - 105 acres if spread across one level.
There are 25 miles (40km) of plumbing, 1,500 miles (2,414km) of electric wiring, 80 miles (129km) of elevator cable and 145,000 light fixtures, the building's website says.
As Sears' fortunes dipped during the late 1970s and 80s, so too did those of the company's headquarters. Failing to attract new tenants, the building stood half-empty for several years.
Sears moved out to smaller headquarters in the early 1990s, and the skyscraper has had a number of other owners since then.
Today, Sears Tower boasts several restaurants, a conference centre, fitness centre, broadcast platform and a 160-car underground car park.
French climber Alain "Spiderman" Robert got a first-hand look at the tower's glassy exterior in 1999, when he scaled the enormous skyscraper using just his bare hands and feet.