Caldwell acquired a controlling interested in the Cumberland Telephone and Telegraph Company in 1890. The firm installed telephones in Tennessee,
Kentucky,
Mississippi,
Louisiana, as well as Southern
Illinois and
Indiana. That same year, it merged with the Southern Bell Telephone and Telegraph Company, and Caldwell served as its President. When it merged with the Third National Bank of St. Louis in 1912, he became President of the First and Fourth National Bank of Nashville. Caldwell was a major shareholder of the Rodessa Oil and Land Co. In 1937, he was ordered by the chancery court to surrender his stock to cover some of his son Rogers's debt to the State of Tennessee. ==Personal life==