John B. Walker (1898-1986) was, at different points in his career, the founding Vice-President of TWA, the Assistant to the President for United Airlines, and the President of Walker & Crenshaw, Inc. Published works included two books, War in the Air and How to: Get Into Aviation. In addition to his professional positions, he was also a member of many associations and clubs, particularly aviation-related, including being an OX 5 Certified member of Aviation Pioneers and a founding member of the Wings Club. Significant to this collection was his extensive involvement with the creation and activities of the "Conquistadores del Cielo" (Conquerors of the Sky), of which he was a founding member, president, and chairman. The Conquistadores del Cielo were first thought up by Walker and TWA President Jack Frye while on a weekend trip to the Forked Lightning Ranch in New Mexico. After inviting fellow aviation executives and enthusiasts to share in a later weekend retreat, Walker and Frye developed the idea to begin a "club" with the spirit of aviation as its centerpiece. The original retreat was held in 1937. Conquistadores del Cielo was organized by the following year's (1938) retreat at the Brush... Valley and Forked Lightning Ranches.