Working as a longshoreman during his teenage years on the docks of Charlestown and East Boston, he would become close friends with future president of the International Brotherhood of Teamsters Local 25, William J. McCarthy.

His best friend however, was Joseph "Joe Mac" McDonald, a very tough and feared Somerville man who was the first to organize crime on Winter Hill.

McLean began to slowly amass a formidable criminal organization due to the admiration of his ability to fight along with a strong sense of street smarts.

[1] In early September 1961, two Winter Hill associates of McLean, and their friend, Charlestown mobster George McLaughlin rented a cottage on Salisbury Beach for a Labor Day party.

He killed Bernie McLaughlin walking out of the Morning Glory bar in Charlestown in broad daylight and in front of almost one hundred witnesses on October 31, 1961.