He arrived in New Orleans, but ended up living in Webster Groves, Missouri. The following is a biographical sketch of Henry that was published in the "History of St. Louis County," by William L. Thomas, 1911, pg. 72-77:
The record of Henry Prehn is but another illustration of the fact that character and ability will always come to the front, no matter what the early environment of a man may have been, for from a humble position he has worked his way up in the business world until he ranks among the men of prominence in commercial and financial circles in Webster Groves.
He was born in Germany on the 21st of January, 1833, a son of John Henry and Margaret (Kniff) Prehn, who passed their entire lives in the fatherland. In the schools of his native country Henry Prehn acquired his education and he assisted his father in the work of the home farm until his ambitious spirit prompted him to seek advancement in the business world. Determining to try the opportunities which he heard were open to enterprising youth in the new world he left home and friends and sailed for America, arrive at New Orleans in April, 1857. He continued his journey up the Mississippi river to St. Louis, Missouri, and thence to Gasconade county, this state, where he remained for a short time.
When he returned to St. Louis his entire capital amounted to but two dollars and fifty cents and he at once sought work by which he could provide for his support. He engaged in truck gardening around that city for about six months, after which he came to Webster Groves, and here was employed at various occupations, scorning no avenue through which he could earn an honest living. His time was thus employed until 1867 when, with the money which he had been able to save as a result of constant exertion, unfaltering perseverance and the most rigid economy, he purchased a small stock of goods and opened up a grocery store at this place, with which line of activity he has since been identified. The business had a small beginning, but its gradual expanse, in time, made it one of the most important enterprises of its kind in the city. In 1875 he added a feed department and his trade has now reached most gratifying proportions. The secret of his success lies in the fact that he has never been afraid of work, laboring earnestly and diligently toward the goal of independence, while his methods have ever been honest and aboveboard, never taking advantage of the necessities of others to further his own ends. Putting forth his efforts in financial fields, he assisted in organizing the Bank of Webster Groves and also the Trust Company of Webster Groves, and is now serving as director in both institutions.
Mr. Prehn was married twice. On the 21st of January 1862, he wedded Miss Johanna Leue, and they became the parents of two children: John Henry; and Minnie, the wife of John Carr, of San Francisco, California. The wife and mother passed away in 1871, and on the 21st of January, 1872, he married Miss Mary Caroline Bangert. Unto this union were born nine children, of whom one, John, passed away in infancy. The surviving members are: Louise, the wife of Louis Roemmer, of Pacific, Missouri; Fred, who is associated with his father in business; and William, Carrie, Charles, Robert, Catherine and Walter, all of whom are living at home.
Mr. Prehn and his family hold membership in the First Congregational church of Webster Groves and are well known in the social circles of his community. During the time of the Civil war he served as sergeant of the Home Militia, and in politics he has ever been a stanch republican, giving his allegiance to the party which stood as the support of the Union during the dark days of the Rebellion. He served as postmaster of Webster Groves under the administration of President Hayes, but aside from that office has never sought nor desired political preferment. No citizen, however, is more deeply interested in the welfare of the community in which he resides, for not only has he been progressive and successful in business, but has supported every public movement which has to do with the development and improvement of this district, and is a strong advocate of all those things which are a matter of civic virtue and of civic pride. He is a familiar figure in the community in which he has so long labored, and those who know him respect him for his sterling personal worth as well as for the business ability he manifests, and in all relations of life he measures up to the full standard of honorable, upright manhood.