Why We Use QWERTY Keyboards
The layout of your keyboard was designed in the 1870s to solve a mechanical problem that no longer exists.

Christopher Latham Sholes was a newspaper editor in Wisconsin who, along with two collaborators, developed one of the first practical typewriters. His early prototypes arranged the keys alphabetically, in two rows, like a piano. The problem was jamming. Each key on a mechanical typewriter is connected to a metal arm that swings up to strike the paper. When a typist pressed two neighboring keys in quick succession, their arms would collide and stick together, requiring the typist to stop and manually separate them.
Sholes spent years experimenting with different arrangements. His business partner, James Densmore, suggested separating letter pairs that frequently appeared together in English—th, he, an, in—so their arms would approach the printing point from different angles. The solution wasn't about slowing typists down, as is sometimes claimed, but about keeping the mechanical arms from tangling.
By 1873, Sholes had arrived at something close to the modern layout. That year, strapped for cash and tired of development, he sold his patent rights to the Remington Arms Company for $12,000. Remington had the manufacturing capacity to mass-produce typewriters, and when their "Remington No. 1" hit the market in 1874, it carried Sholes's keyboard arrangement. The specific layout—QWERTY, named for the first six letters of the top row—was patented in 1878 and shipped on every subsequent Remington model.
Alternatives have been proposed. The Dvorak layout, developed in the 1930s, claims to be more efficient, placing the most common letters on the home row where fingers naturally rest. Studies have produced mixed results on whether it actually improves typing speed. What's certain is that QWERTY was already everywhere by then, embedded in millions of typewriters and in the muscle memory of everyone who used them.
Computers inherited the layout from typewriters, and typewriters inherited it from a machine whose metal arms needed room to swing. The problem was solved over 150 years ago. The solution is still on your desk.