Here are some photos I took of some examples of the Douglas C-54D Skymaster on display at the Pima Air Museum in Tucson, Ariz., during a visit in the spring of 2017 and at March AFB in 2018. The example at Pima is a veteran of the Berlin Airlift in 1949, and wears the markings of that campaign although many modifications were made afterward.
The specially modified VC-54C “Sacred Cow” was built to transport Pres. Franklin D. Roosevelt.
The C-54 is the military version of the DC-4 commercial aircraft.