Inspired by the exploits of Iron Man, circus archer Clint Barton decided to put on a costume and fight crime as the super-hero Hawkeye. At first he was mistaken as a criminal, but Barton eventually gained the trust of the Avengers and has served on that team with distinction many times.Marvel Source
In addition to his pinpoint accuracy, Hawkeye relies on a quiver full of gadget arrows with various high-tech tricks. But even without his arrows, he's a formidable combatant thanks to hours of training with Captain America.
His sarcastic wit sometimes rubs allies the wrong way, but Hawkeye remains one of the most loyal and dedicated Avengers in the team's history.
Update 12/30/13: Replaced Triple Shot with Double Shot. Everything I've been hearing states that double is the way to go.