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