He had many of his early fights in Puerto Rico, where he lived for a short period of time, with victories over the likes of Ron Warrior in 1984, and had a shot at the WBA junior middleweight title in August 1986 against champion Mike McCallum. Jackson hurt the defender on a couple occasions in the first round, but McCallum came storming back with a barrage that forced the referee to stop matters in the second round. Jackson then had his second crack at the title in November 1987 on the Chavez-Rosario undercard, and left the ring this time with a belt around his waist - the same WBA 154-lb. title he had failed to win from McCallum the previous year. Julian's rival was Korean Baek In-Chul, who was disposed in three rounds. (In-Chul, by the way, would eventually win the WBA super middleweight title a year or so later). Jackson then made three inside-the-limit defenses of his crown, against former IBF world champion Buster Drayton (TKO 2), Francisco DeJesus (KO 8), and future WBC champion Terry Norris (TKO 2). Jackson then vacated his crown, moved up to 160 lbs., and was pitted against Herol Graham for the middleweight division's vacant WBC title in Spain. Graham was ahead on the judges' cards for three rounds, but Jackson knocked Graham out in round our to conquer his second career world title . Defenses against Dennis Milton (KO 1), Ismael Negron (KO 1), and Ron Collins (TKO 5) ended quickly, but Thomas Tate would make Jackson work longer and harder in their August 1992 encounter - Julian had to go to the scorecards for the first time in a title bout in winning a 12-round unanimous decision. That would lead to his showdown in May 1993 with Gerald McClellan. This time the challenger prevailed, flooring Jackson twice in the fifth round, the second knockdown which prompted the referee to stop the fight and award the belt to McClellan. Jackson had another shot at the title in May 1994 in a rematch with McClellan, but was knocked out in the first round. Jackson would then have a second but brief reign as WBC middleweight champion again, beating Agastine Cardamone by knockout in March 1995 to win the same belt vacated by McClellan, but then promptly losing the title in his first defense against Quincy Taylor in August of that year by a ninth-round knockout. Jackson's career would then go into a tailspin, finishing up with a negative streak whose most important bout perhaps was a ninth-round knockout loss to Verno Phillips in January 1998. Jackson's nickname is The Hawk.
He works at the St. Thomas tourist attraction, Coral World.