Simplify the following text for a Grade 6 native English-speaking person.
Original: Cormier became a full-time writer after the success of his first novel for teenagers , The Chocolate War , followed by others such as I Am the Cheese and After the First Death .
Simplified: Cormier became a full-time writer after his first novel for teenagers , The Chocolate War , became successful . Then he wrote other books such as I Am the Cheese and After the First Death .