McDonnell Aircraft Corporation was an American aerospace manufacturer founded in 1939 by James S. McDonnell. The company specialized in designing and producing military aircraft, including the famous F-4 Phantom II, which became a key fighter jet during the Vietnam War. McDonnell Aircraft played a significant role in the development of various aircraft for the U.S. military and contributed to the space program. In 1967, McDonnell Aircraft merged with Douglas Aircraft Company to form McDonnell Douglas Corporation. This merger expanded the company's capabilities in both military and commercial aviation. McDonnell Douglas continued to innovate until it was acquired by Boeing in 1997, further solidifying its legacy in the aerospace industry.