The Pineapple Primary was the name given to the primary election held in Illinois on April 10, 1928. The campaign was marked by numerous acts of violence, mostly in Chicago and elsewhere in Cook County. In the six months prior to the primary election, 62 bombings took place in the city, and at least two politicians were killed. The term "Pineapple Primary" originates with the contemporary slang term "pineapple" to describe a hand grenade.