Hanson was born 27 August 1827 in Clark County, Kentucky. He fought during the Mexican war as a member of a Kentucky volunteer regiment. Returning to Kentucky he studied the law and began a practice. He was wounded in the leg while fighting a duel. The injury earned him the nickname "Bench Leg". He tried his hand at politics running unsuccessfully for a seat in the US Congress from Kentucky's 8th district in 1857. During the secession crisis he took a conservative stance, backing John Bell in the 1860 presidential election.

Although he favored neutrality when the war began Hanson saw Union troops moving into his native state as an invasion and joined the Kentucky State Guard. He was named colonel in the guard on 19 August 1861. On 3 September 1861 when the state guard was incorporated into the Confederate army Hanson was named colonel of the 2nd Kentucky. He was given command of the 1st Kentucky brigade. His penchant for discipline earned him the nickname "Old Flintlock". When Union troops occupied Lexington, Kentucky in September 1861 and the 1st Kentucky was forced to leave the state the brigade became known as the "Orphan Brigade". Hanson and his command were sent to help garrison Fort Donelson, Tennessee and were surrendered on 16 February 1862. Hanson would be held as a prisoner of war until he was exchanged on 27 August 1862 for Michael Corcoran, a colonel in the 69th New York who was captured at 1st Bull Run. Hanson was promoted to brigadier general on 13 December 1862. He commanded the 4th Kentucky brigade assigned to John C. Breckinridge's 1st division in William J. Hardee's Corps at Stones River. When the division was ordered by Braxton Bragg, the Army of Tennessee's commander, to make a suicidal assault on the Union lines on 2 January 1863 it is said that Hanson talked of going to army headquarters to kill Bragg for ordering such an assault. Instead he led his brigade in the assault and was mortally wounded. He died two days later on 4 January 1863.

Roger W Hanson