He was originally an itinerant space traveller of the mid-23rd century, when in stardate 1/9304 he happened upon a planet that had been long-abandoned by its former Orion inhabitants. He discovered that it was a rich source of pharmaceuticals and laid claim to it shortly before the breakout of the Four Years War. Though a single-person claim to an entire planet was quite often easy to make but hard to keep, the events of the war kept others from challenging his claim.
In stardate 2/0410, after the war, Holcomb returned to the planet with his family and a number of settlers to found a colony, now named Holcomb's Planet. Several Orion families petitioned the Federation for a permit to settle on the planet, and Holcomb became a champion for their cause until it was approved.
Holcomb soon found himself a very wealthy man due to the planet's rich supply of pharmaceuticals. The Holcomb family founded a number of corporations: Holcomb Pharmaceuticals, Holcomb Construction and Excavation, Holcomb Mining, and Holcomb Computers. Harry Holcomb administered the planet for and later retired, leaving affairs to his sons.
In retirement, Holcomb operated the best sports-fishing fleet out of the planet's capital city of Orlando.
He had a wife, four sons and a daughter. His four sons jointly managed the Holcomb's Planet, while his wife and daughter owned Holcomb Pharmaceuticals.
Harry Holcomb and his family were highly regarded by the Orion community of Holcomb's Planet, and even by a number of Orions off-world. They were considered heroes who had achieved the Orion ideal of starting with nothing and rising to the top, though they tended to be embarrassed by it, at least in public. Harry Holcomb in particular was sometimes referred to as a rhadaman anthus, or "prince of executives," a title he proudly wore on a baseball cap when out fishing. (FASA RPG module: The Orions: Book of Common Knowledge)