Jackson was born in
New Bern, North Carolina, and his family relocated to
Brooklyn, New York when he was a child. He played for the
Boys High School basketball team alongside
baseball player
Tommy Davis and future
Basketball Hall of Famers
Lenny Wilkens and
Connie Hawkins. It was while playing for the
Virginia Union University basketball team, however, that Jackson's leaping ability took off. He averaged over 20
rebounds per game and was known for jumping over the defender's head on fast breaks. He was the
CIAA freshman of the year in 1958. During the summertime, he played on the Brooklyn All Star team in the Rucker Park Tournaments, along with his childhood friend Connie Hawkins and
New York Knick Walt Bellamy. He built his playground status by
dunking over
Wilt Chamberlain and also blocking his
finger roll in the same game. ==Professional career==