Share This Article 1. The Area-51 facility was established in 1955 to develop this aircraft. The SR-71 The U-2 The F-117 The F-111 2. This country’s general staff was the first to use the “staff ride” as a training exercise. France Austria Great Britain Germany 3. On 7 April 1862 this Confederate stronghold on the Mississippi surrendered. Cairo, Illinois Island No. 10 Fort Donelson Vicksburg, Mississippi Loading …