John W. Caldwell was born in
Russellville, Kentucky, on January 15, 1837. He was the son of Austin and Louisa (Harrison) Caldwell. Austin Caldwell died in 1843, leaving John Caldwell as his only living child. With the duties of caring for his father's estate, Caldwell was only able to attend the common schools of
Logan and
Christian Counties until age fourteen. In 1850, he moved with his uncle, Dr. Robert Peyton Harrison, to
Texas, where he worked on a farm, as a clerk, and as a surveyor. At age nineteen, Caldwell returned to Kentucky. He studied law with William Morton, a well-known lawyer in his family. In 1856, he matriculated to the
University of Louisville School of Law, completing a junior year course of study with honors. He graduated from the university in 1857, was
admitted to the bar in 1858, and commenced practice in
Russellville, Kentucky. Caldwell married Sallie J. Barclay, and the couple had one son and two daughters. ==Civil War service==