In the book's own words, not ours, with obvious scanning errors fixed. Families often supplied these stories to the publisher, so check key dates.
From The History of Clark County Ohio, (1881)
J. C. OLDHAM, dentist, Springfield. The name of Oldham has been associated with the dental profession of Springfield for more than a quarter of a century. Mr. Oldham’s father, M. M. Oldham, whose wife was Calista Taft, removed to Springfield from Cambridge, this State, in 18538, and successfully practiced here until within the past few years, his health failing, he has spent the most of his time in the South, leaving the business almost entirely to his son J. C., who has been a partner with him since 1874. The subject of this sketch was born in Cambridge in 1846, and came with his parents to Springfield in 1853. Having a natural taste for the profession, he improved the opportunities afforded by his father's office and practice, and, when but 15 years of age, was able to make artificial sets. In 1864, although but 17 years of age, he enlisted in the 153d O. N. G., and experienced the hardships of army life in thefield. After which, in addition to the instructions received from his father, he took a regular course and graduated at the Ohio Dental College, at Cincinnati, and subsequently practiced for a time in the office of his cousin William Taft, a well-known and successful dentist of the Queen City. Since 1874, he has been a partner with his father. "Having the advantage of a thorough knowledge of his profession, and the latest and best improvements in tools and material and having a natural taste for and pride in his work, he has now a valuable reputation for first-class work, and, being well and favorably known. enjoys a liberal patronage. He is a member of the State Dental Association, and also of the Mississippi Valley Dental Society. He married, in 1877, Miss Josephine, daughter of Joseph L. Morris, who is closely related to the Longworths, of Cincinnati, and formerly resided there, but is now a resident of Springfield..
As printed in The History of Clark County Ohio, (1881). See the original pages. Wording is the original; obvious scanning errors have been corrected, and a few may remain.
The printed record stops around 1881. We trace your line from there down to you, with every source cited.