Here's why:
* Common noun: A general name for a person, place, or thing. It is not capitalized.
* Proper noun: A specific name for a person, place, or thing. It is capitalized.
In the sentence, "Tallchief" is a proper noun (a person's name), and "Indian Achievement Award" is also a proper noun (a specific award name). The word "award" is a common noun because it refers to the general concept of a prize or recognition.