Complex sentence: The name was changed to Dow Army Field in 1942, and in 1947, when the newly formed US Air Force took control, it became Dow Air Force Base and part of the Strategic Air Command (SAC).
Split into simpler sentences: The name was changed to Dow Army Field in 1942. In 1947, when the newly formed US Air Force took control, it became Dow Air Force Base and part of the Strategic Air Command (SAC).