In 1860, he was enumerated on 25 Jun on the census return for Nebraska City, Otoe Co., NE, and was listed as an attorney, age 29, b. SC, along with his wife, Rosina L., age 20, b. VA, and son, "Floyd" D., age 3 mos., b. DC. He was also enumerated on 14 Jul in Ward 3, Washington, DC, and was listed as an attorney, age 28, b. SC, along with his wife, Rosina L., age 22, b. VA, and son, "Lloyd" D., age 2 mos., b. DC. Thus, it would appear that they moved from NE to DC abt. Mar 1860.
According to the U.S. and International Marriage Index, 1560-1900, Thomas Jefferson MACKEY, b. 1830, m. Rosina LLOYD.
In 1880, he was a circuit judge in Chester, SC.
Hope this helps a little.