Complex sentence: Standing 6' 3 "tall and with" fists large as hams, "McCormack forced his way into a position of enormous power, wealth and political influence and for almost 30 years was known as the mysterious" Mr. Big of the New York City waterfront.
Split into simpler sentences: Standing 6' 3 tall, and with "fists as big as hams," McCormack forced his way into a position of enormous power, wealth and vast political influence. For almost 30 years he would be known as "Big Bill McCormack," the mysterious "Mr. Big" of the New York City waterfront.