Kiernan was born in
Mountbellew,
County Galway, in 1837. His father was a retired
British Navy surgeon. Kiernan attended
Trinity College, Dublin, before emigrating to the USA about 1854. On the outbreak of the Civil War in 1861, he joined the
69th New York Infantry Regiment as Assistant Surgeon. He served as such at
Bull Run and in the same capacity to the
6th Missouri Infantry Regiment at
Pea Ridge. Kiernan insisted on joining the fighting ranks and, in that capacity, was seemingly appointed a Major in the 6th Missouri. In May 1863 at
Port Gibson,
Mississippi, he was wounded in the left lung and left on the field for dead. Recovered and imprisoned, he effected an escape back to Union forces and resigned his commission. On 1 August 1863, he was commissioned a
brigadier general of
Volunteers by President
Abraham Lincoln, commanding a post at Miliken's Bend on the Mississippi. However, ill-health as a result of his battlefield wounds forced him to resign on 3 February 1864. About May 1865, he gained a US consular post at
Zhenjiang in China. However, his continued ill-health forced him to return to New York, where he became an examining physician for the
Pension Bureau. He was still serving in that capacity upon his death on 26 November 1869; the official cause of death being '
congestion of the lungs.' He is buried in
Green-Wood Cemetery in
Brooklyn. ==See also==