First Lieutenant Mills was with his brothers in Charlie Company, 1st Battalion of the 2nd Marines (C-1/2) when they landed on Betio as part of Operation: GALVANIC. The mission of the 2nd Marine Division was to secure the island in order to control the Japanese airstrip in the Tarawa Atoll; thereby preventing the Japanese Imperial forces from getting closer to the United States, and enabling US forces to get closer to mainland Japan. It would become one of the bloodiest battles in the Corps history.

First Lieutenant Mills was with his brothers in Charlie Company, 1st Battalion of the 2nd Marines (C-1/2) when they landed on Betio as part of Operation: GALVANIC. The mission of the 2nd Marine Division was to secure the island in order to control the Japanese airstrip in the Tarawa Atoll; thereby preventing the Japanese Imperial forces from getting closer to the United States, and enabling US forces to get closer to mainland Japan. It would become one of the bloodiest battles in the Corps history.