Wikipedia has this to say:
Beef Stroganoff, in its simplest form, is simply tender beef with a mushroom and sour cream sauce served over rice or noodles.
The current accepted history of this dish dates back to the 1890s when a chef working for Count Pavel Alexandrovich Stroganov, the famous Russian general, invented the recipe for a cooking competition in St. Petersburg. After the fall of Imperial Russia, the recipe was popularly served in the hotels and restaurants of China before the start of the Second World War. Russian and Chinese immigrants, as well as U.S. servicemen stationed in pre-communist China, brought several variants of the dish to the United States, which may account for its popularity during the 1950s. It is commonly served with noodles or rice.