The start of the war led to the dissolution of the treaty system, but the dramatic need for new vessels precluded a new design, so the Clevelands used the same hull as their predecessors, but were significantly heavier.

Following the start of World War II in September 1939, Britain announced it would suspend the treaty for the duration of the conflict, a decision the US Navy quickly followed.

[2] The ship's belt armor ranged in thickness from 3.5 to 5 in (89 to 127 mm), with the thicker section amidships where it protected the ammunition magazines and propulsion machinery spaces.

Other ships in the division included Miami and Houston — the latter perpetuating, like Vincennes, the name of a man-of-war lost earlier in action with Japanese surface units.

[3] Departing Boston on 16 April, Vincennes subsequently transited the Panama Canal and ultimately reached Pearl Harbor, Territory of Hawaii, on 6 May.

During one of the ship's in-port periods that interspersed the at-sea training evolutions, Admiral Chester W. Nimitz came on board Vincennes and presented her embarked flag officer with a Navy Cross — won for directing bombardment operations in the Aleutians.

[3] In the days that ensued, Vincennes supported the carriers as they launched aircraft to smash Japanese positions on Saipan and Pagan Islands on 12–13 June.

During the key Battle of the Philippine Sea, Vincennes' gunners performed their tasks well, aiding materially in the barrage of gunfire that broke up several of the enemy's nevertheless persistent attacks.

[3] On 23 June, Rear Admiral Baker shifted his flag to Vincennes' sister ship Miami, releasing the erstwhile flagship to proceed to Eniwetok, in the Marshalls, for needed engineering repairs.

Dropping anchor at Eniwetok on the 27th, Vincennes completed her repairs by the end of the month; she subsequently sailed to rejoin CruDiv 14, and Rear Admiral Baker brought his flag to the ship again on 7 July.

[3] Assigned next to TF 34, Vincennes departed Eniwetok at the end of August and conducted tactical and gunnery exercises until joining TG 38.2 on 3 September.

The next day, 7 September, Vincennes, as part of Task Unit 38.2.5 (TU 38.2.5), under Rear Admiral Whiting, embarked on board, conducted the first shore bombardment on Japanese installations on the southernmost Palau cluster of Peleliu, Ngesebus and Angaur islands, the ship's captain subsequently recording that the coverage of the areas shelled was "excellent".

Friendly fighters on combat air patrol (CAP) duties overhead proved invaluable, knocking down many enemy aircraft that ventured too close.

The enemy knew no set time to attack — Vincennes observed a "Betty" being shot down within sight of the ship during the task force's fueling-at-sea evolutions the next day.

[3] Vincennes and her sisters next shaped course for Formosa, as the fast carriers shifted their operating area to prepare the way for the upcoming onslaught against the Japanese-occupied Philippine Islands.

En route to Formosa, Japanese planes frequently showed themselves, but maddeningly stayed out of range — persistent and pugnacious snoopers that always managed to slip away untouched.

[3] On 12 October, the carriers began launching air strikes against Formosan sites; that afternoon, the task group gunners proved exceptional, downing a pair of "Betties" that ventured too close.

Put together on 16 October, the force served its purpose; Vincennes participated in the withdrawal, screening her crippled sister-ship and division mate, and Canberra.

Enemy snoopers closed the formation on several occasions; detected early on the 24th, a Japanese four-engined flying boat — a Kawanishi H8K "Emily" — went down in flames to the guns of friendly fighters.

The ship experienced several determined air attacks on the 29th, but the CAP proved ready to accept the enemy's challenges, downing eight Japanese planes during the course of the raids.

[3] Vincennes continued her vital screening duties on 5–6 November as carrier planes carried out strikes on Japanese positions and installations on Luzon.

At 12:46, Vincennes fired on enemy aircraft in the vicinity; three minutes later, the light cruiser teamed with Miami to blast a kamikaze from the sky and into the sea.

During scheduled gunnery exercises, a radio control target drone crashed into the splinter shield of one of Vincennes' 40 mm mounts, bursting into flame.

After American carrier-based planes had hit Japanese installations on Kyūshū, determined enemy attacks on the formation kept Vincennes' gunnery department busy on the 18th.

On 31 March, two of Vincennes' floatplanes cooperated in rescuing a downed fighter pilot in spite of heavy enemy fire; Lt. Evans, commended earlier, received the Distinguished Flying Cross, while Lt.

Sailing via Pearl Harbor, Vincennes reached Mare Island Navy Yard on 8 July and remained there until the availability was completed in late August.

[3] Vincennes then participated in Operation Magic Carpet following her refresher training, sailing between Pearl Harbor and the west coast as a transport for returning sailors and Marines.

On 25 October, the ship got underway to take Rear Admiral Hendren on an inspection tour of facilities at Guadalcanal; in the Russells; at Tulagi; at Espiritu Santo; and Efate, returning to Nouméa on 5 November.

Discharging them at San Francisco upon her arrival on 23 March 1946, the light cruiser sped to Mare Island where workmen soon commenced deactivating the ship.

Struck from the Navy list on 1 April 1966, she was sunk as a target in missile experiments[3] in the Pacific Ocean off the coast of Southern California near Point Mugu, on 28 October 1969.