By the 1960s, the US Navy envisioned that large scale convoy operations would be needed in the event of a war against the Soviets. As the Soviets maintained a considerable amount of submarines this makes escorting every single convoy impossible with just carrier groups. The Sea Control Ship (SCS) - a cruiser/frigate scaled version helicopter carrier with the ability to also operate harrier fighters from their deck was thought to be able to fill such roles.
However, a dedicated ship built for such purpose was eventually rejected - rather than building dedicated escort carriers like the ones in World War II, the US simply built amphibious assault ships with a flat-top deck to operate helicopters and harriers. In fact, the move was rather successful.
The design of the SCS however, will see fruitation in form of the Spanish carrier Principe de Austurias.