Major General Clayton Vogel, who commanded the Amphibious Corps, Pacific Fleet, recommended after Guadalcanal that the program be expanded significantly — that the original twenty-nine trained Code Talkers be supplemented by several hundred more, that training be institutionalized at a dedicated facility, and that the system be developed from a pilot program into a core element of Marine communications doctrine.

His recommendation was accepted.

The expansion of the program from its experimental origins to a substantial component of Marine communications infrastructure was one of the most consequential administrative decisions of the Pacific war.

What the early Code Talkers had proven at Guadalcanal was not simply that the code worked.

They had proven that it worked under the specific conditions that mattered: combat conditions, with inexperienced commanders who had to trust a system they had never trained with, against an enemy that was actively trying to monitor and exploit American communications.

The code had held under pressure.