The C-54 Skymaster:

C-54s began service with the Army Air Forces in 1942, carrying up to 26 passengers. (Later versions carried up to 50 passengers.) The U.S. Navy also acquired the type, under the designation R5D. The C-54 was one of the most commonly used long-range transports by the U.S. armed forces in World War II. 515 C-54s were manufactured in Santa Monica, CA and 655 were manufactured in Chicago, Illinois.

After World War II, the C-54 continued to serve as the primary airlifter of the new United States Air Force and with the United States Navy.

The USAF Strategic Air Command had C-54 Skymasters in service from 1946 through 1975.

President Harry S. Truman signed the National Security Act of 1947, which created the U.S. Air Force, on board "Sacred Cow", the Presidential C-54 which is preserved at the National Museum of the United States Air Force. More than 300 C-54s and R5Ds formed the backbone of the US contribution to the Berlin Airlift in 1948. They also served as the main airlift during the Korean War. After the Korean War, the C-54 was replaced by the Douglas C-124 Globemaster II, but continued to be used by the U.S. Air Force until 1972.   Courtesy Wikipedia: C-54; click for more info

The C-124 Globemaster:

The Douglas C-124 Globemaster II, nicknamed "Old Shakey", was a heavy-lift cargo aircraft built by the Douglas Aircraft Company in Long Beach, California. The C-124 was developed from 1947 to 1949 by Douglas Aircraft from a prototype created from the WWII-design Douglas C-74 Globemaster and based on lessons learned in the Berlin Airlift. The aircraft was powered by four large Pratt & Whitney R-4360 piston engines producing 3,800 horsepower each. The C-124s design featured two large clamshell doors and a hydraulically-actuated ramp in the nose as well as a cargo elevator under the aft fuselage. The C-124 was capable of carrying 68,500 lb of cargo, and the 77 ft (23.5 m) cargo bay featured two overhead hoists, each capable of lifting 16,000 lb (7,000 kg). As a cargo hauler, it could carry tanks, guns, trucks and other heavy equipment, while in its passenger-carrying role it could carry 200 fully equipped troops on its double decks or 127 litter patients and their attendants. It was the only aircraft of its time capable of transporting heavy equipment such as tanks and bulldozers without prior disassembly.

The first flight of a C-124 took place on November 27, 1949. The C-124A was followed in service by the C-124C, which featured more-powerful engines as well as wingtip-mounted combustion heaters that provided cabin heating and wing and tail surface deicing, and an APS-42 weather radar in a distinctive nose "thimble." These latter improvements were eventually retrofitted to the C-124As.  Courtesy Wikipedia; C-124; click for more info

 The C-141 Starlifter:

The Lockheed C-141 Starlifter was a military strategic airlifter in service with the United States Air Force. Introduced to replace slower piston-engined cargo planes such as the C-124 Globemaster II, the C-141 was designed to requirements set in 1960 and first flew in 1963. Production deliveries of an eventual 285 planes began in 1965: 284 for the Military Airlift Command, and one for NASA. The aircraft remained in service for almost 40 years until the USAF withdrew the C-141 from service on May 5, 2006, replacing the aircraft with the C-17 Globemaster III.

The company was awarded a contract in 1961 for five aircraft for test and evaluation to be designated the C-141. One unusual aspect of the aircraft was that it was designed to meet both military and civil airworthiness standards. The prototype C-141A serial number 61-2775 was manufactured and assembled in record time, being rolled out of the factory at Marietta, Georgia on 22 August 1963 and first flying on 17 December. The company and the Air Force then started an operational testing program and the delivery of 284 aircraft, initially to units of the MATS (later renamed Military Airlift Command).

On 16 September 2004 the C-141 left service with nearly all active duty USAF units, being confined to reserve units for the remainder of its service life. As of 25 September, 2005, there were only eight C-141 aircraft still flying (all from the 445th Airlift Wing at Wright-Patterson AFB). In 2004, 2005, and 2006, the C-141s stationed at WPAFB participated in missions to Iraq and Afghanistan, mostly for the medical evacuation of wounded service members.  Courtesy Wikipedia; C-141; click for more info