The history of DC motors goes as far back as the 1830's and are now so customizable that they are widely used for applications across many industries.
A Brief History of DC Motors - Motor Specialty Inc.
Basics of Armatures - Motor Specialty Inc., Armature
Company History Motor Specialty Inc.
Electric motors
Motor Specialty Inc.
Company History Motor Specialty Inc.
DC Motors -- Background and history
News - A brief history of motor development
The Early History of the DC Traction Motor, The Railway Technical Website
Top motor control driver considerations for DC motors
DC Motor: What Is It? How Does It Work? Types, Uses