Unfortunately, the biography written by Marcella Coolidge, Cassius's daughter, is not currently available. I received a notice (from someone unaffiliated with Marcella) that posting her complete biography is a copyright violation. After looking into it further, I have determined (with my nonexistent legal background) this is probably the case, even though I am giving her the entire credit for the work. It is unfortunate that I am unable to share it, since it contains many details about Cassius and his childhood. Laws are laws though, and I do not feel like putting up with more stress than necessary.
You may still read my own unofficial biography, although it is not nearly as good.