[1] He spent four years serving as a First Lieutenant, and eventually an Officer of Procurement in the United States Army during the implementation of The Marshall Plan while stationed in Germany after WWII.
He remained politically active his entire career, later becoming an aggressive advocate for effective governing of oil industry regulations.
He served as president of the oil and gas company from 1968 to 1975 and as chairman of the executive committee and co-chairman of the board of the exploration firm from 1975 to 1977.
[2] Because of his diagnosis and ongoing treatment for Chronic Lymphocytic Leukemia, Mr. Rankin retired from active management in 1977, and continued to serve in the capacities of Vice Chairman of the Board and Consultant to the Company, and Member of the Board of Directors, Executive Committee and major shareholder until his passing.
The company eventually merged with Freeport Minerals, forming Freeport-McMoRan while maintaining McMoRan Exploration as a subsidiary.
'[4] Rankin purchased a stake in the Texas Rangers in the early 1980s, becoming a minority owner and sitting on the team's six-man board of directors.
Equally passionate about the opportunities of college sports, he was asked to lead the fundraising campaign for the expansion of the Darrell K. Royal Texas Memorial Stadium.
[4] Mr. Rankin was the proud Co-Founder and Chairman of the Chronic Lymphocytic Leukemia Global Research Foundation, now nationally recognized by M.D.
Anderson's inclusion in their far-reaching Moon Shots Research Program, one of only six departments of the Cancer Center so recognized.