Carter Winston was the foremost Human trader and philanthropist of the 23rd century. Winston had acquired a dozen fortunes only to use his wealth time and again to assist Federation colonies in times of need or disaster.
In 2259, the colony of Cerberus experienced a crop failure, and the entire population (including Leonard McCoy's daughter Joanna) was in danger of starvation. Winston saved the people of Cerberus by using his personal fortune to bring in enough food and goods to carry the colony through the crisis.
Winston went missing in 2264, when he was engaged to Starfleet officer Anne Nored. Winston's one-man ship was disabled in a meteor storm and crashed on the planet Vendor. Winston lived under the care of a Vendorian until 2265, often speaking of his love for Nored before succumbing to his injuries.
The truth behind Winston's disappearance was not discovered until 2269, when Winston was seemingly discovered alive and adrift in his ship near the Romulan Neutral Zone by the USS Enterprise. The vessel's occupant was, in fact, the Vendorian shapeshifter who had cared for the real Winston on Vendor, now working as a Romulan spy. His strong feelings for Nored were absorbed and thus shared by his impersonator. (TAS: "The Survivor")
Carter Winston makes a brief but significant appearance in the final chapters of the Star Trek TOS novel The Final Reflection, where he assists in the brokerage of a deal with the Klingon Empire for advanced warp technology.