A war chest is a term used to describe a large sum of money that is set aside for a specific purpose, often related to military or political campaigns. The phrase originated in the 17th century when armies would collect funds from supporters and store them in wooden boxes called "chests" before going into battle. These chests were used as a way of storing weapons, supplies, and other necessary items for warfare.
Over time, the term has evolved to refer to any large sum of money that is saved or collected for a particular purpose, whether it be for military campaigns, political elections, charitable donations, or business investments. The phrase "war chest" now conveys the idea of having a significant amount of funds available for use in pursuit of a specific goal.