Final answer:
The main contributions of Savannah and Brunswick during World War II were their roles in the production and supply chain, as well as their involvement in shipping resources to support the American and Allied forces.
Step-by-step explanation:
The main contribution of the port cities of Savannah and Brunswick to the American war effort in World War II was their role in the production and delivery of war material and supplies. As vital components of the United States' military logistics, these port cities were integral in ensuring that soldiers across various theaters of war received the necessary equipment and provisions. Savannah and Brunswick became key sites for shipping resources across the Atlantic, significantly contributing to the success of American and Allied forces. The ports also played a part in the construction of Liberty Ships, which were quickly built cargo ships that transported troops, arms, and other vital supplies, playing a pivotal role in the Allied victory. Their strategic location and infrastructure enabled efficient transport and distribution of wartime materials essential to maintain the efforts of the American military and their personnel.