The Fargo-class cruisers were a modified version of the Cleveland-class cruiser design; the main difference was a more compact pyramidal superstructure with single trunked funnel, intended to improve the arcs of fire of the anti-aircraft (AA) guns. The same type of modification differentiated the Baltimore and Oregon City classes of heavy cruisers, and to a lesser degree the Atlanta and Juneau classes of light cruisers. Changes were made in order to reduce the instability of the Cleveland-class light cruisers, especially their tendency to roll dangerously. The main battery turrets sat about a foot lower and the wing gunhouses (the 5 inch, twin gun mounts on the sides of the ship) were lowered to the main deck. The medium (40 mm) anti-aircraft mounts were also lowered.