Immediately following the Guadalcanal campaign the remaining ships of the class went through major overhauls to lessen top-heaviness caused by new electrical and radar systems and anti-aircraft weaponry which had been added as technology advanced.

The Bureau of Construction and Repair authorized a contemporary 8-inch (203 mm) gun cruiser design of smaller size, but one which allocated considerably more tonnage towards protection.

Protection represented approximately 15% of normal displacement as opposed to only 5.6% in the Pensacolas and 6% in the Northampton and Portland classes.

When the US entered the war in December 1941, the New Orleans class and other "Treaty" cruisers were rushed into battle with little modification and lacking in air defense.

The Japanese proved at Pearl Harbor and with the sinking of Prince of Wales and Repulse off Malaya that this war would be decided with air power.

As the war progressed, developments in radar abilities gave the Allies an increasingly decisive advantage over the enemy.

The forward superstructure had the bridge wings cut back, and all of the large size windows were plated in with just a few port holes taking their place.

In addition several gun tubs were created for the 40 mm Bofors mounts both around the main mast, and aft.

The forecastle deck extended back to the second funnel and the main superstructure was constructed without the ungainly tripod mast seen on the previous cruisers.

Aircraft handling facilities were moved further aft and a larger second conning station erected above the hangar.

A single mainmast was erected there, between two huge pedestal cranes which handled both spotter planes and small craft.

By enlarging the forecastle deck, the secondary battery of 5-inch guns were mounted closer together, facilitating a more efficient ammunition delivery.

While many changes were implemented to improve their performance and especially their protection, the 10,000-ton limit of the Washington Naval Treaty was not exceeded.

For almost four years, the ships of the New Orleans class were assigned to the most urgent of front line duties, becoming involved in much deadly action.

Damage control work and skillful seamanship kept these ships afloat to continue to fight through the end of the war.