"The map details the areas where certain usages predominate.
• coke: this generic term for soft drinks predominates throughout the South, New Mexico, central Indiana and in a few other single counties in Nevada, Utah and Wyoming. ‘Coke’ obviously derives from Coca-Cola, the brand-name of the soft drink originally manufactured in Atlanta (which explains its use as a generic term for all soft drinks in the South).
• pop: dominates the Northwest, Great Plains and Midwest. The world ‘pop’ was introduced by Robert Southey, the British Poet Laureate (1774-1843), to whom we also owe the word ‘autobiography’, among others. In 1812, he wrote: A new manufactory of a nectar, between soda-water and ginger-beer, and called pop, because ‘pop goes the cork’ when it is drawn. Even though it was introduced by a Poet Laureate, the term ‘pop’ is considered unsophisticated by some, because it is onomatopaeic.
• soda: prevalent in the Northeast, greater Miami, the area in Missouri and Illinois surrounding St Louis and parts of northern California. ‘Soda’ derives from ‘soda-water’ (also called club soda, carbonated or sparkling water or seltzer). It’s produced by dissolving carbon dioxide gas in plain water, a procedure developed by Joseph Priestly in the latter half of the 18th century. The fizziness of soda-water caused the term ‘soda’ to be associated with later, similarly carbonated soft drinks.
•Other, lesser-used terms include ‘dope’ in the Carolinas and ‘tonic’ in and around Boston, both fading in popularity. Other generic terms for soft drinks outside the US include ‘pop’ (Canada), ‘mineral’ (Ireland), ‘soft drink’ (New Zealand and Australia). The term ‘soft drink’, finally, arose to contrast said beverages with hard (i.e. alcoholic) drinks."
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