The second USS Charleston (C-2) was a United States Navy protected cruiser — the fourth US protected cruiser to be built. Lacking experience in building steel cruisers, the design was purchased from the British company Armstrong, Mitchell and Co. of Newcastle, the construction to be by an American shipyard. In design, she succeeded the "ABC" cruisers Atlanta, Boston, and Chicago with better protection, higher speed, and similar armament.

Protected cruisers, a type of cruising warship of the late-19th century, gained their description because an armoured deck offered protection for vital machine-spaces from fragments caused by shells exploding above them. Protected cruisers resembled armored cruisers, which had in addition a belt of armour along the sides.