SAT Question: Do all prepositions need an object?

Can anyone explain what this sentence is saying?

“In many of his works Tennessee Williams, of whom much has been written, has as main characters drofters, dreamers, and those who are crushed by having to deal with reality.”

I feel as if the sentence would be better if there had been an “about” after written. Do all prepositions need an object?

Thanks

Hi myc

First of all, I assume “drofters” is a typo and should be drifters.

The sentence uses the preposition ‘of’ instead of ‘about’ and the object of ‘of’ is ‘whom’ (i.e. Tennessee Williams)

I’ll rephrase the sentence as two sentences:

There has been much written of/about Tennessee Williams.
Tennessee Williams wrote about drifters, dreamers, and those who are crushed by having to deal with reality.

Amy

If “about” and “of” were both included in that phrase, we’d have a case of redundancy – saying the same thing twice, two times, dos veces, etc. (hehe)