Seeing Bowie down, the nearby Major Norris Wright (an old rival of Bowie's, who once got into a fistfight with him after denying Bowie a bank loan) saw his chance to rid the planet of Bowie once and for all. He fired, but missed. The wounded Bowie noticed, shot back and hit Wright. This is when Wright, who we were totally picturing as Dick Dastardly even without this next part, drew his cane sword and plunged it into Bowie's chest.
Bowie Knife Fights, Fighters & Fighting Techniques
Jim Bowie, in happier days, fighting a bandit while nailed to a log.
Bowie went down, as men pierced by swords are wont to do. However, the blade sat tight in his chest. The gloating Wright couldn't wiggle it out, so he put his foot on Bowie's chest to pull out the sword. That was just the opening Bowie (who apparently had treated the whole "he's wiggling a sword in my chest" thing as little more than an elaborate ruse) had been waiting for.
He grabbed Wright's leg, dragged the screaming man down and disemboweled him with his trusty hunting knife ... while the poor man's cane sword was still very much stuck in his own chest.
G.T. Johnson II
The fight, known later as the Sandbar Fight, made Bowie's name and guaranteed him and his knife a place in the pantheon of Wild West icons.
Later in life, when James Black created the famous version of the bowie knife made legendary by the fight, Jim adopted one ... and tried it out by killing three assassins who jumped him. He would probably still be walking the earth and swinging big blades at bankers if he hadn't happened to be in the Alamo when being in the Alamo was a really bad idea.