Anytime I go back to England, I try to remember to bring a copy of Colin Woodard’s “American Nations” with me to bestow on friends who want to know what on earth is going on in the United States. The book came out in 2012, just as the Tea Party and the Culture Wars were cresting; its insights into the country’s different regional origins made those movements all begin to come into focus. Four years later, in “American Character,” he honed his ideas further: into the national search for a balance between individual liberty and the common good. I concluded my review in these pages thus: “Colin Woodard’s essential thesis is vital to understand. It’s not his fault that it cannot explain the silliness of this year’s (2016) primary season.”

His new book, “Union,” “drills down” still deeper. As the 19th century got underway, and the first generation of patriots succumbed to old age, the concept of one America – necessary as it had been during the war for independence – started to crack. What it meant to be an American needed to be defined. In a kind of chronological quincunx that rolls over the course of a century, Woodard uses the life and writings of five men to follow the resulting struggle. In an initial Note from the Author, he leaves them unidentified, and I freely admit that I could guess only two of them.

The first pair – one Northern and Harvard-educated, the other Southern and largely self-taught – were born at the very beginning of the century. I think it’s safe to say neither George Bancroft nor William Gilmore Simms are household names, but they were very famous in their day and Woodard’s colorful writing and formidable research talents make both come alive.

By contrast, Frederick Douglass, born the following decade, is known even to Donald Trump (just). Together, the preoccupations of these three men, enormously different in every way, take the story through the Civil War and Reconstruction. The narrative moves forward via concurrent events in each of their lives told in mostly short chapters, one after the other. One is less than a third of a page.

It happens to be the chapter that introduces the fourth of his characters, three-year-old Tommy Wilson, who “as an adult… would go by his middle name, Woodrow.” Partly because Wilson was already the country’s fourth 20-century president (and thus qualitatively closer to us in time than the others) and partly because of his reputation as an international statesman and creator of the League of Nations, his effort to re-assert the white “ethno-nationalist” state is especially shocking. In his “make the world safe for democracy” speech, which brought the United States into the First World War, Wilson proclaimed, “Its peace must be planted upon the tested foundations of political liberty.”

Woodard pulls no punches: “He then proceeded to destroy those very foundations at home.”

The fifth man in “Union” was “perhaps the most famous American scholar of his age,” Frederick Jackson Turner. Five years younger than Wilson, he laid “the groundwork for a later revolution,” writes the author.

“Union, The Struggle to Forge the Story of United States Nationhood,” by Colin Woodard. Viking, 2020; 417 pages; $30 Cover courtesy of Penguin/Random House

Initially, Turner saw American history and the formation of the American character as a function of battling the frontier. Later, he saw physical geography as a greater factor. As the frontier moved westward, a true American would evolve out of the old European roots in response to the land; “like Darwin’s finches in the Galapagos,” comments Woodard. “The data, however,” he goes on, “kept confounding this hypothesis…. Had he been prepared to accept that culture, not geography, was the more determinative force, the answer would have been obvious.”

“Union” is an eye-opening piece of history, no more so than in the chapters on D.W. Griffith and “The Birth of a Nation.” To those for whom the idea of different American nations is a compelling one, the book provides insight into how racially-blinkered all attempts to forge a national story e pluribus unum have been. It’s worth noting that not one of “Union’s” protagonists questioned the right to expand across the continent or the consequent displacement of the original inhabitants.

Once again, Woodard, who is a reporter at the Portland Press Herald, has produced a story that could not be more timely. Whether one is tracking the coronavirus through the lens of the 11 American nations (which he did in last week’s paper), or reacting to Trump’s divisive rants, the struggle between rugged individualism and community spirit shows no signs of abating. As he writes, “Its contours make this a sobering and cautionary tale for readers today.” Once again: Colin Woodard’s essential thesis is vital to understand. It’s not his fault that it cannot bridge the terrifying chasm of this year’s presidential election.

Thomas Urquhart lives in Falmouth. His new book, “Up for Grabs, a history of Maine’s Public Reserved Lands,” will be published in 2021.