What is the tallest skyscraper in the world?

The word skyscraper was first applied to such buildings in the late 19th century, reflecting public amazement at the tall buildings being built in Chicago and New York City. The structural definition of the word skyscraper was refined later by architectural historians, based on engineering developments of the 1880s that had enabled construction of tall multi-story buildings. This definition was based on the steel skeleton—as opposed to constructions of load-bearing masonry, which passed their practical limit in 1891 with Chicago's Monadnock Building. Philadelphia's City Hall, completed in 1901, still holds claim as the world's tallest load-bearing masonry structure. The steel frame developed in stages of increasing self-sufficiency, with several buildings in Chicago and New York advancing the technology that allowed the steel frame to carry a building on its own. Today, however, many of the tallest skyscrapers are built more or less entirely with reinforced concrete. In the United States today, it is a loose convention to draw the lower limit on what is a skyscraper at 150 metres. Elsewhere, though, a shorter building will sometimes be referred to as a skyscraper, especially if it is said to "dominate" its surroundings. Thus, calling a building a skyscraper will usually, but not always, imply pride and achievement.