Whenever I feel a twinge of despair over America’s challenges—a not infrequent occurrence—I ask myself a simple question: “What year or decade would you like to return to?” It’s a useful exercise for anyone harboring undue pessimism about the future or gauzy nostalgia for the past. Americans have a tendency to take much of our long-term economic, technological, medical, and social progress for granted, while assuming that our current problems will only get worse. History shows that such fatalism is unwarranted.

For example: In 1991—the year that America’s violent-crime rate reached its highest level on record—no one could have predicted the massive, nationwide crime drop that was about to begin. Likewise, as late as 2010—when the International Energy Agency’s chief economist declared that “the age of cheap oil is over”—few people could have foreseen the impact of the shale revolution. Of course, sometimes things do get worse: A half-century after Daniel Patrick Moynihan sounded the alarm over nonmarital childbearing, more than 40 percent of U.S. births occur outside marriage. Meanwhile, the labor-force-participation rate among prime working-age men is hovering near all-time lows, and deaths from heroin use have been skyrocketing.

The point is: Different metrics tell different stories about how our country has changed, for better and for worse, over the past several decades. Thus, a one-dimensional narrative of decline or triumph is misleading.

All of this may seem a strange way to introduce a book entitled Letters to Santa Claus. Yet while reading it I kept thinking of our journey as a nation: where we’ve been, where we are, and where we’re going. The title is not a metaphor; this really is a collection of letters and envelopes—more than 250 in total—that were addressed to Santa Claus and forwarded by the post office to the town of Santa Claus, Indiana (population 2,500). It includes a foreword by Pat Koch, founder of the town’s Santa Claus Museum & Village, who started helping her father answer the Santa Claus letters in the 1940s. Koch’s father was Raymond Joseph “Jim” Yellig, who dressed up as Santa, worked at Santa Claus Land, and “was truly the face of Santa Claus, Indiana, for many, many years.”

Spanning nine decades, from the 1930s through the 2010s, the letters provide a window into the ever-shifting economic and cultural landscape of modern America. They are alternately silly and somber, hilarious and heartfelt. In a letter from the Depression era, a 9-year-old girl in Woodstock, Maryland, asks Santa to bring her brothers and sisters some winter clothes, lamenting that “we are poor and got no money for toys or candy.” She then lists the names and ages of her siblings before adding, “and the others are dead”—delivering an abrupt reminder that child mortality was considerably more commonplace in the 1930s than it is today. (Between 1935 and 2010, the mortality rate among American children aged 1 to 4 fell by 94 percent.)

By the 1950s, America was a richer, healthier place, yet still poor by the standards of 2015. In 1953, an 8-year-old Chicago girl tells Santa that “our daddy still doesn’t come home and mama cries at night when she thinks we are asleep, because she has no money for our coats and shoes and some dolls for Christmas.” One wonders if this girl had lost her father in the Korean War. In 1970, another Chicagoan, a father with eight children, earnestly asks Santa to help his family meet their basic food and clothing needs, explains that they don’t own a house or car—and then feels compelled to add: “We do not get any help or aid from the city.”

To be sure, there is lighter fare here, such as a letter from a cheeky husband in Pittsburgh requesting “some lovely new lingerie” for his wife, a letter from a 10-year-old Kansas girl warning Santa to “be careful this month and don’t break your leg,” and another from an Ohio girl asking if Santa was around “when the dinosaurs lived.” And it’s interesting to see how the quantity and sophistication of children’s gift requests have increased over time. In 2008, a boy from Campbellsville, Kentucky, asks Santa for a $479 laptop computer, a laptop case (“It’s only $15.00 so I can pay for it my self”), a $29.96 wireless Internet connection card, and a $69.98 two-year service plan. If these items prove too expensive, he says in a postscript, “tell my mom and dad to deduct the money from my birthday and next years Christmas.”

Letters to Santa Claus demonstrates just how much wealthier America has become since the mid-20th century. Yet it also reminds us that, despite our success in reducing material want, more and more children have been growing up in chaotic, broken, or never-formed families. “My mom and I had to move in with Nana + Papaw to help us through some rough times,” writes a Virginia boy in the 1990s. “A man called a Judge, gave me a new Mommy,” says an Indiana girl in 2002. Five years later, a girl from Hope, Arkansas, declares, “All I want for Christmas is my mom and dad to celebrate Christmas with there family. Also I want them to stop arguing and for them to be safe. Also can you get me a locket with a picture of my mom and dad[?]”