Thomas Reade Rootes 'T.R.R' Cobb (1823-1862) was born in Jefferson County, Georgia, to John Addison Cobb (1788-1855) and Sarah Rootes Cobb (1792-1865). In 1842, he graduated from the University of Georgia and afterward practiced law in the Western Circuit of Georgia. In 1844, he married Marion Lumpkin (1822-1897), daughter of the Georgia Supreme Court Justice Joseph Henry Lumpkin (1799-1867) and Callender 'Callie' Cunningham Grieve Lumpkin (1803-1871). Thomas and Marion had six children; Lucy Cobb (1844-1857); Sarah Addison Cobb Jackson (1845-1915); Callender McHenry Cobb Hull (1848-1911); Joseph Henry Lumpkin Cobb (1850-1851); Thomas Reade Rootes Cobb (1852-1853); and Marion Birdie Cobb Smith (1860-1919).

From 1849 to 1857, T.R.R. Cobb worked as reporter for the Georgia Supreme Court. In 1859, he founded the Lucy Cobb Institute, a girls' school located in Athens, Georgia, named in honor of his eldest daughter who died of scarlet fever. He also served as a delegate to the Georgia Secession Convention in 1861 and wrote a treatise in support of slavery titled, An Inquiry into the Law of Negro Slavery in the United States of America. During the Civil War, Cobb served in the Confederate Congress as chairman of the Committee on Military Affairs. In the summer of 1861, he organized Cobb's Legion and was commissioned as a colonel in the army. He was promoted to brigadier general in November 1862. At the Battle of Fredericksburg in 1862 he was mortally wounded in the thigh by an artillery shell.