His autobiography might be worth checking:
'Myself', Macmillan, New York, 1934
L. G. Harter's 'John R. Commons: His Assault on Laissez Faire', Oregon
State University Press, Corvallis, 1962, might also contain some
information.
A more recent essay on Commons' work is:
Ramstad, Y. (1990), "John R. Commons: Theoretical Foundations of a
Volitional Economics", Research in the History of Economic Thought and
Methodology, 8, pp. 53-104
Chris R. Tame