A Year Down Yonder is a classic coming-of-age tale because it chronicles Mary Alice Dowdel's transition from childhood to young adulthood. When Mary Alice shows up at her Grandma Dowdel's house, she's a teenager who thinks that she knows everything—but it turns out that she has quite a bit to learn.
Over the course of the novel, we watch Mary Alice grow more mature as she considers how she can take care of her grandmother (instead of the other way around), and even witness her falling in love for the first time. Goosebumps! (Not that kind of goosebumps.)
Of course, this book also qualifies as historical fiction, since it's firmly set in the late 1930s, just after the Great Depression. In addition to getting the flavor of small town life during that era, we also become familiar with terms like the Roosevelt Recession, the Works Progress Administration, and, of course—the Twitter of that time—the Philco radio.
And even though it's the tail end of the Depression, Mary Alice still witnesses—and experiences firsthand—a lot of financial worry and people having to go without. That gives us insight into the difficulties of the Depression era (with things like new clothes and pie considered the greatest extravagances), and how it felt for people when their family members and loved ones went overseas to serve in the war.