....while the US did have aircraft carriers, up until the Pearl Harbour disaster the US always considered the Battleship the heart of the fleet. It took the near complete destruction of Battleship Row, to prove the viability of the carrier as a weapon in its own right.
A popular misconception. Permanent battleship losses at Pearl Harbor were two, Arizona and Oklahoma. Most heavily damaged was West Virginia, then, somewhat in order of severity, were California, Nevada, Tennessee, Maryland, and Pennsylvania. All of these last six were repaired, some obviously taking longer than others, modernized, and returned to the fleet.
Not damaged, simply because they were not at Pearl Harbor, were Wyoming (gunnery training), Arkansas, New York, Texas, New Mexico, Mississippi, Idaho, Colorado, North Carolina, and Washington. So there were nine battleships (not counting Wyoming) undamaged, more than were at Pearl Harbor at that time of the attack, including the two newest, North Carolina and Washington.
There really wasn't an epiphany of "oh, crap, our battleships have been wiped, guess we'll have to resort to carriers." It was well recognized in the US Navy that the fleet carrier was not only faster than all of the existing battleships, but also a more versatile striking platform. Of those not at Pearl Harbor, speed-wise, only North Carolina and Washington even came close with rated top speeds of about 27 knots. A Yorktown class carrier could easily beat that. Doesn't seem like much, but when moving at top speed under combat conditions, that means the carrier could eventually out distance the slower battleship, conceivably making it superfluous. The older battleships were lucky to crank out 21 knots maximum.
The easiest illustration of this is Enterprise and Saratoga going out in November 1941 to ferry aircraft to Wake and Midway. In both cases, it was decided to leave the battleships behind as they would not contribute to the operations and would only serve to slow down the task group.
The funny thing about battleships is that, while, true, they can pile a lot of iron on a beach, they are really designed for one purpose and one purpose only, to poke holes in the other guy's battleships. Carriers, on the other hand, have the ability to reach out well beyond gunfire range and deliver killing blows to any size enemy ship, from battleships on down. The down side to carriers is that they require escorts to provide AAA and submarine defense coverage. Such escorts need to be relatively speedy and heavily armed for the purposes intended. Cruisers, especially of the AAA type, and destroyers fit the requirements nicely. And, true, while a battleship can provide considerable AAA fire, and incidentally serve as a bomb magnet, it also requires a certain amount of escort and aerial protection and so causes an unhappy division of resources.
A similar example of the deliberate decision to leave battleships out of the equation was Nimitz's decision to leave his available battleships in the vicinity of the west coast of the US during the Midway operation. While, to an extent this was to appease the Nervous Nellies in Washington, he also knew that they would be of little value in what was sure to be a pure aircraft carrier engagement. Their presence would have merely served to slow down the carriers, dilute his available escorts, and force the carriers to provide protective CAP when there was painfully none to spare.
New battleships authorized after the expiration of the Naval Limitation Treaties and completed were as below. Note that all were started before the US entered WWII, and indeed, three of them before WWII even started in Europe.
North Carolina, laid down 27 October 1937
Washington, laid down 14 June 1938
South Dakota, laid down 5 July 1939
Indiana, laid down 20 November 1939
Massachusetts, laid down 20 July 1939
Alabama, laid down 1 February 1940
Iowa, laid down 27 June 1940
New Jersey, laid down 16 September 1940
Missouri, laid down 6 January 1941
Wisconsin, laid down 25 January 1941
Authorized, pre-war, but never completed, or, in most cases, never even started, battleships are listed below. It should be kept in mind that some of these were to be replacements for such obsolescent BBs as Arkansas, New York, and Texas.
Illinois (laid down 6 December 1942, canceled 12 August 1945)
Kentucky (laid down 7 March 1942, suspended 17 February 1947, canceled 1958)
Montana (not started, canceled 21 July 1943)
Ohio (not started, canceled 21 July 1943)
Maine (not started, canceled 21 July 1943)
New Hampshire (not started, canceled 21 July 1943)
Louisiana (not started, canceled 21 July 1943)
Significantly, once the war started for the US, no new battleships were completed that had not already been started prior to 7 December 1941, and after some 18 months of war, all new planned battleship construction was canceled, and neither of the two BBs started after Pearl Harbor were completed. Further, no other new battleships were authorized.
On the other hand, there were authorized prior to the US entry in to WWII thirteen Essex class carriers. Authorized in June 1940 were three: Essex, Yorktown, and Intrepid. Another ten (Hornet, Franklin, Ticonderoga, Randolph, Lexington, Bunker Hill, Wasp, Hancock, Bennington, and Boxer) were, a month later, authorized. After the US entered the war an additional 19 Essex class carriers were authorized between July and September 1942. Of these six were canceled on 28 March 1945, as they were never started, and the under construction Reprisal and Iwo Jima were canceled on 12 August 1945. In all, twenty four Essex class carriers were completed. Off the top of my head, fourteen of them saw combat service in WW2. Also constructed were another 9 CVLs and, without counting fingers and toes, about 99 CVEs.
So, just on the basis of authorizations, with 13 Essex class carriers, before the US entered the war, the argument could be made that the aircraft carrier was already on its way to becoming the leading capital ship of the USN before battleship losses and damage in the Pearl Harbor attack.
Rich