Andrew first married Nancy A. Smith, the daughter of Henry Smith and Eve Hickam from Boone Co. MO. I was unable to locate a marriage record for Nancy A. Smith to A.J. Pittman. There is a marriage record of a Lucinda Smith to Andrew Pittman 23 Mar 1844 in Andrew Co. MO. I have no idea if this was them, and if so why it said Lucinda. Their son Andrew J. Pittman Jr, born 1851, said he was born in Andrew Co. Mo.

Nancy A. Smith married Andrew Jackson Pittman circa 1844, their first child (Pleasant Lily Pittman) being born Sept 1845.

They are in the Aug 15, 1860 census living in Bonfemme Twp, Howard Co. MO. with the following children:
Pleasant, 12
Andrew J, 10
Levi, 8
Joseph, 2
William P, 12

They leave Missouri and reappear in the 19 July 1870 census farming in Red River Co. Texas:
Andrew, 46 TN
Nancy 46, MO
Pleasant, 21
Andrew, 18
Levi, 16
Joseph, 12
Lucinda, 6

They returned to Missouri and Nancy died in 1873. Her husband Andrew J. Pittman remarried a Melvina Robertson (20 yrs his junior). Melvina had been previously married to a Haggard as she brought stepchildren into the marriage. The 1880 Polk Co. MO census:
AJ Pittman, 58
Melvina, 36, wife
Pleasant L., 33, son
Luisa, daughter-in-law, 22 (Louisa Robertson, wife of Pleasant)
Joseph Pittman, 21, son
Kisiah J., (Keziah Jane "Janey" Roark), daughter-in-law, 21, wife of Joseph; married 1879
Marian Evans Pittman, 15, niece
Lucinda Pittman, 13, daughter
Calvin Pittman, 6, grandson
Charles Pittman, 4, grandson
Fannie Pittman, 1, granddaughter
WT Haggard, 6, b. Arkansas, stepson
Anna Lee Haggard, 5, b. Arkansas, Stepdaughter

1900 Census in Cooke County, TX:
Andrew Pitman, 77, TN, 21 years married, head; Melvina Pitman, 56, IN, wife; Annie Haggard, 25, AR, stepdaughter.

Although he had remarried, Andrew J. Pittman was buried with wife Nancy.