Correction: An earlier version of this review incorrectly referred to the river that flows through the Grand Canyon as the Rio Grande. It is the Colorado River. This version has been corrected.

The windy subtitle of Simon Winchester’s engaging new book contains a revealing clue about the author. On any list of characters he considers worthy of attention and admiration, one suspects, eccentrics would have a prominent place. This may be because Winchester is something of an eccentric himself.

He demonstrates this with the definition he offers of this sprawling book project: “The main purpose of [these] pages . . . is to consider what might be called the physiology and the physics of [the United States], the strands of connective tissue that have allowed it to achieve all it has, and yet to keep itself together while doing so.” These strands, Winchester believes, were the achievements of the adventurers he wants to write about, and there are dozens of them. Luckily for readers, they were nearly all intriguing characters. But they are also the very definition of a mixed bag.

To make a book with some degree of “structure and logic,” Winchester concedes, “a device was needed.” This Englishman who became an American citizen in 2011 lived for many years in Asia, where, he tells us, people have long held the philosophical view that all of creation can be reduced to the essential elements, usually five: “wood, earth, water, fire and metal.” Why not adopt that scheme for a book about the making of “the great magical confusion that is the American nation”? So we get a big book divided into five sections vaguely connected to the five elements. They do give the book an arbitrary structure but not much logic — which doesn’t matter at all.

The fun here is in Winchester’s exuberant enthusiasm for his new country and for the characters he has found who helped shape it.

We begin “when America’s story was dominated by wood,” on the heavily wooded grounds of Thomas Jefferson’s Monticello. There, in 1802, President Jefferson was deciding to launch the expedition we now refer to as Lewis and Clark, named for its leaders, Meriwether Lewis, 28, Jefferson’s private secretary, and William Clark, 32, an Army pal of Lewis’s. Winchester gives us, in fewer than 50 pages, a vivid, exciting and educational re-­creation of their adventures. Wood had little to do with it. But the expedition told Jefferson and his countrymen what a rich land awaited them in the West, the new world opened to them by the Louisiana Purchase in 1803.

“The Men Who United the States America's Explorers, Inventors, Eccentrics and Mavericks, and the Creation of One Nation, Indivisible” by Simon Winchester (Harper. 463 pp. $29.99). (HarperCollins)

Winchester writes even more exuberantly about the exploration of America’s geology, which was his major subject at Oxford in the 1960s. One of his favorite figures is John Wesley Powell, the geologist who led the first expedition through the Grand Canyon, then returned to chart that amazing neighborhood. On his first trip down the Colorado River, Powell had no idea how grand the canyon above him was. Winchester writes:

“Here they were, cold and wet and hungry, a mile deep in the black bowels of the earth, the sky above so distant it was speckled with faint stars even at noon.” From this remote vantage point, Powell and his five companions could not have imagined what was just above them, the “gold, orange and purple” of the canyon, the “delicate cliffs and pinnacles of sunburned sandstone, endlessly repeating themselves in marvelous chaos, to produce one of the most incredible sights on the surface of the earth.”

Other famous creators appear here, Thomas Edison, Samuel F.B. Morse and Henry Ford among them. Winchester does them all justice with his agile pen. But there is more fun to be had from his accounts of lesser-known or simply unknown figures whom he has plucked from obscurity.

For example, John Loudon McAdam, who, from his native Scotland, taught Americans to abandon the traditional method of road building, as old as the Romans, that featured “big slabs of rock, the bigger and tougher the better.” Such roads were often treacherous and unreliable.

Building roads in Scotland, McAdam discovered the benefits of compaction. To last, he found, a road’s top two inches had to be made of compacted stones, small enough to fit into a man’s mouth — large gravel, in other words. One of the first highways built this way was the Cumberland Road, from Western Maryland across Ohio into Indiana, completed in the 1830s. Crushed gravel proved a durable surface. Roads made that way soon became known as macadam. They had just one drawback — they threw up great quantities of dust when dry. Then a Welshman, Edgar Hooley, thought of spraying tar on the macadam surface. This was tarmac, or blacktop.

Another road-builder whom Winchester reintroduces with enthusiasm is Thomas MacDonald, “an iron-willed, curmudgeonly martinet” who ran the federal Bureau of Roads from 1919 to 1953. It was MacDonald who gave the major routes numbers as names and persuaded Congress to appropriate hundreds of millions to build them. Winchester shows that MacDonald and Franklin D. Roosevelt, the fifth president he served, were the real fathers of the Interstate Highway system, not Dwight D. Eisenhower, who usually gets the credit.

Winchester takes his story up to the present, adding the Internet to his collection of adhesives and ties that have bound our vast, continental nation together. Most of his earlier stories are about men who brought the country closer together in some way; it feels ironic that the last is about a technology that has hastened the disaggregation of American society and obliterated a national market for news, especially. He left this reader with the anxious feeling that the future may involve a lot of undoing of the cohesive effects of the past that Winchester describes so well.

If the book’s structure can sometimes bewilder, its largest theme is clear from beginning to end, and it is surprisingly relevant in today’s Washington. “Without an engaged and functioning federal government,” Winchester writes at the outset, the events and heroics he describes, “these various strands of the country’s connective tissue would probably have been either delayed or never achieved at all.” From Lewis and Clark to the engineers who invented the Internet, all Winchester’s heroes either worked for the government or were sponsored by its agencies.

Robert G. Kaiser , an associate editor of The Washington Post, is the author, most recently, of “Act of Congress: How America’s Essential Institution Works, and How It Doesn’t.”

THE MEN WHO UNITED THE STATES

America’s Explorers, Inventors, Eccentrics, and Mavericks, and the Creation of One Nation, Indivisible

By Simon Winchester

Harper. 463 pp. $29.99