The kepi is a cap with a flat circular top and a visor (American English) or peak (British English). Etymologically, the term is a loanword of the French képi, itself a respelled version of the Alemannic Käppi: a diminutive form of Kappe, meaning "cap". In Europe, this headdress is most commonly associated with French military and police uniforms. In North America, it is usually associated with the United States Civil War, as it was worn by soldiers on both sides of the conflict.
Read more about Kepi: French Army - Historic, Modern French Usage, North American Usage, South America, Usage Elsewhere, Non-military Use