Henry J. Southwick was born in 1836 in Stockholm, St. Lawrence County, New York, the son of Lorenzo Dow Southwick (1807-1877) and Eunice (Hart, b. 1810).
Vermonters Lorenzo and Eunice (she had been born in Montpelier) were married probably in Vermont and probably in 1829. Lorenzo was probably living in Fairfax, Franklin County, Vermont in 1830 (he may have been born in Rutland County, Vermont) and he and Eunice were still living in Vermont in 1832 when their oldest child, Samantha was born. By 1835 they had settled in New York and by 1850 Henry was working as a blacksmith along with his father and attending school with his two younger siblings in Norfolk, St. Lawrence County, New York.
Henry left New York, probably with his family, and moved west, eventually settling in Michigan where by 1860 he was a blacksmith working with his father and living with his family in Bellevue, Eaton County (they lived near James Reed, another blacksmith who would enlist in the Band).
Henry stood 5’8” with blue eyes, brown hair and a sandy complexion and was 25 years old and probably still living in Eaton County when he enlisted in Company E on May 13, 1861. He was reported absent sick or wounded in a general hospital from August of 1862 until he was discharged for chronic diarrhea on November 26, 1862, at Camp Convalescent, Virginia.
Henry returned to Michigan and may have been living in the Charlotte, Eaton County area in 1867 when he may have ran as a candidate for constable.
By 1870 Henry was working as a farm laborer and living with his father in Castleton, Barry County.
In 1863 he applied for and received a pension (no. 209602).