Final answer:
The reference information provided does not specify the award the USO presented to the DCC in 1991, only mentioning the Distinguished Service Cross awarded by General George Marshall to Frank Capra in 1945 and the Croix de Guerre received by Jimmy Stewart.
Step-by-step explanation:
The question asks about an award presented by the USO to the DCC in 1991.
From the given reference information, it seems there might have been some confusion, as it only mentions General George Marshall awarding Frank Capra the Distinguished Service Cross in 1945 for his films contributing to the war effort, and Jimmy Stewart receiving the French Croix de Guerre for his military service.
The Distinguished Service Cross is a military decoration, whereas the United Service Organizations (USO) is a nonprofit organization that provides programs, services, and live entertainment to United States service members and their families.