Buck Chisholm worked as an archer for a traveling circus, who also freelanced as an assassin on the side. Although the Swordsman was training a young boy named Clint Barton the art of of acrobats and throwing knives, Buck thought the young Barton would be a better in the ways of the bow. So Buck started training Barton along with the Swordsman. Both mentors tried to persuade the young Barton into a criminal career, but to no avail.
Trickshot was created by Tom Defalco and Mark Bright.
Years later Buck found-out that he had cancer so he tracked Barton down to die in a final battle. Barton won, but spared his life.
Now the cancer is in remission, he still freelances himself to the highest bidder.
Recently the cancer has returned. Trickshot was apparently was captured by Baron Zemo was was acting as a benefactor for Barney Barton. Zemo withheld cancer treatment from Trickshot while he was force to train Zemo's young protege in the skills of archery, much in the same way he trained Hawkeye.
Zemo had the new fully trained archer drop off the the sick Trickshot whose cancer was fully metastasized on the doorstep of the Avengers in a act to taunt Hawkeye. Trickshot soon succumb to cancer with Hawkeye at his side.