Clinton Francis Barton or Clint, born in Iowa, had a very average childhood. However, as he reached adolescence, he started to develop a talent for marksmanship with a bow and arrow. As an adult, Clint fell in love with his would be wife Laura and the couple eventually got married and had three kids together. He was later discovered and recruited by Nick Fury to join S.H.I.E.L.D. as a potential agent because of his remarkable skills. Fury was the only one who knew about Clint's family (prior to Natasha) and helped him keep the family off the S.H.I.E.L.D. records, and set up a home for them in a farmhouse in Missouri where they lived under the radar.
Clint used the alias Hawkeye during his time with S.H.I.E.L.D. and became one of the best agents S.H.I.E.L.D. has ever had. In one of his missions, Hawkeye was sent to terminate the Black Widow, a KGB spy and assassin who had turned up on S.H.I.E.L.D.'s radar multiple times. Seeing her potential, Hawkeye recruits Black Widow instead, and the two form a partnership that became one of S.H.I.E.L.D.'s most valuable assets.
Hawkeye, together with Black Widow, are among the founding members of the Avengers. His first mission with the team was the Battle of New York where they fought and defeated Loki and the Chitauri Army. He then left S.H.I.E.L.D. to become a permanent member of the Avengers until after the battle with Ultron, in which he was saved by Quicksilver in a heroic self-sacrifice. Blaming himself for the death of Quicksilver, Hawkeye decides to retire. After the passing of the Sokovia Accords that was initiated due to the collateral damage caused by the battle between the Avengers and Ultron, Captain America reaches out to Hawkeye to help him fight against the accords. In debt to Captain America and Quicksilver's sister Scarlet Witch, Hawkeye agrees to join them and together they fight against Iron Man and the remaining Avengers. They are defeated and Hawkeye is imprisoned for a while, before making a deal with Thaddeus Ross, the Secretary of State, to allow him to be placed under house arrest and in retirement.
The Avengers finally reunite without Hawkeye to fight against Thanos' plan to destroy half of existence in the universe. Unfortunately they do not succeed and the Snap happens. Losing his entire family to the snap, Hawkeye goes into a murderous rage, becoming a violent vigilante and killing criminals based on his own judgment, assuming the alias Ronin. He is then tracked down by Black Widow to be recruited again and help the remaining members of the Avengers to find the Infinite Stones and reverse the effect of the Snap.