How Admiral Pratt planted the US Navy's carrier program

What became of Admiral Pratt's proposal to build four new US carriers during his term as Chief of Naval Operations?

The program evolved through Ranger and early design studies into Yorktown, Enterprise, and Wasp, laying important groundwork for later US fleet carriers.

Pratt first had to turn Lexington and Saratoga into viable operational carriers, then used Ranger to test whether a small purpose-built carrier could provide numbers cheaply. Ranger exposed the limits of that approach, while the design work begun under Pratt grew into the Yorktown class and Wasp and helped establish the lineage from which the Essex class later emerged.