Lanham retired from the military at the end of 1954 as a major general, and joined the Pennsylvania-Texas Corporation of Colt's Patent Firearms. He resigned in 1958 and joined Xerox in 1960 as vice president for Government Relations, retiring from that post at the end of 1970.
Lanham retired from military service in 1954 as a major general and then worked for the Pennsylvania-Texas Corporation of Colt's Patent Firearms before joining Xerox in 1960 as vice president for Government Relations, retiring from that position at the end of 1970.