Robert Monroe Kennedy was a Patent Medicine Proprietor in Pittsburgh from around 1870 until after the turn of the century. Some of the products he sold included Dr Radcliffe's Great Remedy, The Great Vegetable Pain Destroyer, Seven Seals or Golden Wonder, and Carboline. The primary business address for Kennedy & Co was at 114 Wood St, Pittsburgh. In 1866, Kennedy said he was a special agent for this product. The originator of the product is unknown.
In 1888, Fenner's Complete Formulary listed the following formula for "Carboline Hair Grower."
Combine 1 pint of neutral paraffin oil, 4 fluid drachms of tincture cantharides, and 20 grains of euphorbium, and heat for two hours. Strain, and add 4 fluid drachms of oil rosemary, 20 drops of oil cassia, and 5 drops of oil cloves.
Kennedy first registered the word "Carboline" as a Trade Mark for a "Medical Compound" in 1877 (view). He said he had just started selling the brand that year. Thompson registered the brand name as a Trade Mark in 1888. He said the brand name had been in use since 1870. Most likely, that was just a guess on the part of Thompson, because that was when Kennedy originally went into business.
Apparently, sometime around 1888, William J. Thompson bought out the business at 114 Wood Street from Kennedy. Thompson registered the label on the bottle shown that year (Trademark #15,954). Kennedy & Co. was no longer listed after that date and W.J. Thompson & Co. were located at that address from 1888 until 1890. According to Fike, Carboline was advertised at least as late as 1923.