This unidentified male could be the 22 year old male in the 1850 slave census who lived on Robert True's plantation in Montgomery Co., Alabama. Robert True is no longer in the slave census in 1860. His will or estate administration might shed light on the names of the persons he had in bondage. Robert true in the 1850 census also had a male, age 10 whom could be the the son of this unknown man and brother to Bettie Lumpkins.
[S320] 1850 U.S. Federal Census - Slave Schedules, Ancestry.com, (Ancestry.com Operations Inc Date:2004 Place:Lehi, UT, USA), 1,8055::0., The National Archive in Washington DC; Washington, DC; NARA Microform Publication: M432; Title: Seventh Census Of The United States, 1850; Record Group: Records of the Bureau of the Census; Record Group Number: 29 (Reliability: 0).