O'Hara was born in Danville, Kentucky on February 11, 1820. After war was declared on Mexico in May 1846, O'Hara quickly responded to the call for troops. O'Hara went to serve the Confederate Army during the Civil War, where he fought in both the battles of Shiloh and Murfreesboro. On Jun 6, 1867, O'Hara died and was buried in Columbus, GA. However, in 1873 his remains were moved to Frankfort, KY, to rest near the graves of the soldiers who inspired his famous poem.