This book does a good historical treatment of Civil Affairs history.

In Chapter 6, GEN (ret) Tony Zinni touches on Civil Affairs: "In 2009 at a Smart Power conference... I recommended that the military's Civil Affairs organization become a unified command; responsible for integrating all the agencies' efforts and providing the planning, administrative, and logistical support for the interagency teams operating on the ground." — GEN (ret) Tony Zinni