John McClane was born on May 23,1955 in Plainfield, New Jersey. His father was an Irish-American cop at New Jersey itself and his mother was a house cleaner. In his youth, John lost his father, and when he arrived to the period of adulthood, John also lost his mother.
With him being an adult, John arrived to New York City, where he joined up to the NYPD and started as a private. With succeeding being an excellent private at the police, the captain promoted him into rank of police detective. As he finished solving a mystery as a detective, the captain also promoted McClane into the rank of a police lieutanant.