Answer:
"...y'all's new coats and books and shiny new Packards!"
Step-by-step explanation:
Mildred D. Taylor's novel "Roll of Thunder, Hear My Cry" revolves around the Logan family and their life trying to survive in a racist society where many people are attacked merely based on their skin color. The book also deals with how the children, especially Cassie Logan was affected, along with how racism played a huge role in how people perceive others.
The sentence or phrase that provides clues for the readers to understand and know the period of the story was the quote "...y'all's new coats and books and shiny new Packards!" Packards are a type of car prevalent during the early to mid-1990s. And it was this development and the material item that reveals the period.