I wonder how the US military would have looked by December 1941 had intensive rearmament started in 1936 as part of Depression Era stimulus and a reaction to Germany, with a boost again in 1937 with Japan's invasion of China. While the two North Carolina class were laid down in 1937/38 and the first of the SoDak class in 1939, the first eleven Essex class carriers were not ordered until 1940. Move those dates so that the eleven Essex class are ordered in 1938 and enter service in 1940 and Japan won't have any illusions. This may require the US to pull out of any naval treaties.
Historically the order for Essex was placed in Feb 1940 and she was laid down in April 1941. The contractual completion date was April 1944 ie a peacetime build time of 3 years. Even at Nov/Dec 1941 that estimated completion date had only been advanced by 3 months. The other 13 month saving came after the outbreak of WW2, presumably once the yards can go to working round the clock. It was a similar story for the rest of the class ordered in 1941.
So to get them in 1940 and without US involvement in a shooting war the construction needs started before the end of 1937. And then you have the problem that under the 1936 London Treaty, to which the US was a signatory, a Carrier can't exceed 23,000 tons, so a 27,000 ton Essex isn't possible at that point.
And it also means that the Second Vinson Act, historically in May 1938, needs to happen sooner and not contain a restriction on the size of the USN. Historically it only added 40,000 tons of carrier tonnage.
And you need to increase the design capacity of the USN after a long period of stagnation. That was one reason why CV-8 Hornet was built as a minimum change repeat Yorktown and not a new design.
So to achieve what you want you need to
1. Withdraw the US from the Treaty system. Under the WNT no BB can be laid down before 1 Jan 1937. So that only saves 10 months on the North Carolina build. That means withdrawing from the Treaty system at the same time as Japan ie giving notice by the end of 1934. And no 1936 London Treaty. So you can get your Essex by 1940 skipping the Hornet.
2. Ensure that US legislation was changed from the WNT limits to allow a much higher / unlimited navy type tonnage.
3. Expand design capacity in the USN or use the civilian sector to a much greater extent.
Now persuade the US public of the need for all this in 1934 not your proposed 1936. That is before Hitler reoccupied the Rhineland (March 1936) and the Abyssinian Crisis (from late 1935). And it is also before tensions with Japan really began to ramp up.
Edit:- one other point. CV-7 Wasp used up the last of the available US carrier tonnage under WNT. So the tonnage is not available to lay down an Essex sized carrier before 1Jan 1937 assuming 1 & 2 above.