Jonah:
I would rank the ones I have read as follows, best at top (though none of
the following is bad):
Fuess (by a mile — real sympathy with his subject… totally out of print)
Sobel
McCoy
Coolidge (that is, his autobiography)
Not that the autobiography isn’t worth reading — it has a wonderful
Coolidgean charm to it. It just doesn’t tell you anything.
(“Fuess,” btw, is pronounced to rhyme with “peace.” He was Bush 41’s
headmaster at Andover.)
There are some fine shorter pieces, too — Gamaliel Bradford on Coolidge’s
spirituality (can’t find the reference), Mencken’s obituary essay (on the
internet somewhere),…