James Barr "Jim" Armstrong was born March 13, 1816, in Pendleton District, South Carolina, son of William Armstrong Jr. and Harriet Rachel Robinson. In 1828, when Jim was 12 years old, he moved with his family to Georgia. The family lived in Georgia for about six years then moved on to Alabama in 1834, settling in that part of Randolph County that later became Cleburne County.

In about 1839, in Randolph County, Alabama, Jim married Elizabeth Jane "Eliza Jane" Porter, who was born December 27, 1821, in McMinn County, Tennessee, one of 11 children born to Henry Porter and Scott Scarborough. Sometime prior to 1835, she moved to Randolph County, Alabama, with her parents and siblings.

Jim and Eliza remained in Randolph County, and had 14 known children: an infant who died at birth in 1839 in Alabama; William Hamilton Armstrong born May 7, 1840 in Randolph County, Alabama; Marion T. Armstrong born 1842 in Randolph County, Alabama; John Franklin Armstrong born March 23, 1843 in Randolph County, Alabama; Isabelle Narcissa Armstrong born about 1844 in Alabama; Sarah Jane Armstrong born about 1845 in Alabama; James Jasper Armstrong born October 17, 1846 in Cleburne County, Alabama; Andrew Jackson Armstrong born about 1849 in Randolph County, Alabama; Samuel Barr Armstrong born June 25, 1850 in Randolph County, Alabama; Henry Thomas Armstrong born May 1853 in Randolph County, Alabama; Rachel Parthenia Armstrong born April 25, 1855 in Randolph County, Alabama; Francis Marion Armstrong born about 1856 in Randolph County, Alabama; Ann Dama Adaline Armstrong born March 19, 1859 in Randolph County, Alabama; and Jefferson Davis Armstrong born July 17, 1861 in Randolph County, Alabama.

The 1850 Federal Census for Beat 4, Alabama (Randolph County) listed James B. Armstrong, a farmer, age 34, born in South Carolina. His wife, Eliza J., was age 28, born in Tennessee. Living with them were six children, all born in Alabama: William, age 10; John F., age 8; Sarah J., age 5; James J., age 4; Andrew J., age 2; and Samuel B., age 0.

Jim was a slave owner, like his father and grandfather before him, with large tracts of land to work. His southern way of life as a slave owner would be forever changed by the civil war. Jim's oldest son, William Hamilton, enlisted in the Confederate service in June 1861. Jim's second son, John Franklin, enlisted one month later and his third son, James Jasper, enlisted in November 1863 when he became 17. Family rumor is that a fourth son, Andrew Jackson, age 13 and too young to fight in the war, served as a messenger for Lee's forces.

The Company Muster Roll for Wade's 8th Cavalry, Company C, 2nd Regiment, Mississippi and Alabama Cavalry, shows that a J. B. Armstrong enlisted on November 14, 1861. This means that Jim enlisted as a Private in the Confederate Calvary when he was age 45 years old, leaving his wife alone with a number of children. Jim's second son, John Franklin, was wounded twice in battle and recovered, but died at age 22 when he was wounded the third time, and was buried in Georges Creek Cemetery in Somervell County, Texas. Jim's sons, William Hamilton, and James Jasper, were both captured in the Battle of the Wilderness and were prisoners of war until it ended.

When the war ended, Jim and his two sons, William and James, went back to Randolph County, Alabama. Their slaves had been freed and the country was in a turmoil. In 1869, Jim packed up his family and moved to Texas. They settled first in Hill County, Texas, then moved on to what is now Somervell County in 1872.

The 1870 Federal Census for Precinct 3, Texas (Hill County) (Hillsboro Post Office) listed James B. Armstrong, a farmer, age 54, born in South Carolina. His wife, Jane, was age 50, born in Tennessee. Living with them were 10 children: Andrew J., age 22, born in Alabama; Samuel B., age 21, born in Alabama; Henry T., age 13, born in Alabama; Francis M., age 13, born in Alabama; Jeff Davis, age 9, born in Alabama; Sarah J., age 25, born in Alabama; Rachel P., age 16, born in Alabama; Dama A., age 11, born in Alabama; William H., a farmer, age 30, born in Alabama; James J., a farmer, age 23, born in Alabama. Also living in the household was Lucy P. Armstrong, age 26, the wife of William Hamilton., born in Georgia; Leana Armstrong, age 4, daughter of William Hamilton., born in Alabama; and Susan F. Armstrong, age 17, wife of James Jasper, born in Tennessee.

Jim died on February 9, 1883, in Somervell County, Texas, and was buried there in Georges Creek Cemetery. Eliza died on May 14, 1878, and was buried beside her husband.