Gin is, arguably, one of the most classic liquors that you can still find readily available. Spirits flavored with juniper date back to Ancient Greece, but the direct antecedent to modern gin is known as genever gin and was brought to England by the Dutch sometime in the 1600s. There, the British changed the formula into the now common London dry gin.
For many years gin was considered a quintessentially British spirit. It was exceedingly popular with all levels of society and Plymouth Gin (widely considered the global gold standard) was standard issue in the British Royal Navy for many years. As the British Empire spread around the globe it brought gin with it, and much of the history of the spirit is tied to this global imperialism. The Gin and Tonic, for example, was originally concocted to ward off malaria in India due to the quinine in tonic water.
In America, gin took hold as the spirit of choice during the prohibition years of the 1920s and 1930s. Ideally gin is made as a neutral grain alcohol that is infused with juniper and other flavors (depending on the brand) in the last couple stages of distillation. However, back in the days of bootleggers and moonshine, gin was the best choice for producing cheap and crude booze because distillers could produce pure grain alcohol and then use juniper extract to cover up the poor quality.
Gin remained the most popular base spirit for cocktails up until the 1950s, when vodka became the more “modern” choice. As a result, many of the vintage cocktails that are regaining popularity are gin cocktails, which will hopefully bring respect back to this classic and complex spirit in our modern age of flavored vodkas.