David McCullough's popular biographies of Theodore Roosevelt, Harry Truman and John Adams succeeded because they weren't about politics or history from a particular point of view, but because they were about real people who happened to be politicians and history makers.

He brought out the humanity in these iconic figures, although he tamped down Roosevelt's blood lust, Truman's suspect background and Adams' snobbery. Instead, he emphasized their strengths, above all their "American" qualities.

Orville and Wilbur Wright don't belong in that select company, despite McCullough's sincere efforts to elevate these hardworking brothers to the American pantheon.

Although this new biography, "The Wright Brothers," refreshes their often-told story in McCullough's upbeat, minutely researched manner, something's lacking — interesting characters. While the brothers accomplished their goal of powered flight, they missed out on the stuff that makes life interesting — relationships, children, hobbies, fun and, most of all, self-reflection.

McCullough essentially ends his biography in 1910, seven years after the Wrights' Flyer went airborne for just under a minute with Wilbur at the controls in Kitty Hawk, N.C. By focusing on their shared triumphs — Wilbur died of typhoid fever in 1912 at 44 — the author avoids the negative sides of the Wrights' remarkable achievement, which included a fight with the Smithsonian Institution over the first manned flight and an ugly patent lawsuit.

Wilbur and Orville grew up in a family of five siblings mostly in Dayton, Ohio, where their father was a minister. Their mother died in 1889 when they were 22 and 18, respectively. Wilbur had become a recluse after he was smashed in the face with a hockey stick at 19 and abandoned plans to attend Yale University.

McCullough believes Wilbur's three years at home gave him time to study the prospects of manned flight. Orville, however, was hard at work as a printer, having built his own press, and was cranking out a neighborhood newspaper.

Wilbur joined his brother in the business and the pair soon became a team of craftsmen, eventually opening a bicycle company. Wilbur continued to follow his interest in flying by seeking help from the Smithsonian, which provided him with a list of sources about the subject.

Thus began the brothers' trial-and-error pursuit of flight, taking them to the Outer Banks, where they tested their theories first on manned gliders, then, in 1903, with a glider equipped with an engine and propellers. Their first flight was Dec. 17, 1903.

McCullough's account of this well-known history is refreshingly told with a wealth of details. Once confident in their machine, the brothers tested it back home, where their airplane flights drew wide attention.

It was the Wrights' efforts to sell their plane in Europe that made them successful as well as famous. McCullough lavishes his full attention on those years spent largely in France. The U.S. Army also bought their plane.

Wilbur continued to work strenuously to market the plane and fight legal battles, but he enjoyed a moment of triumph when he flew around Manhattan along the Hudson River and over the Statue of Liberty in 1909.

For McCullough, the Wright brothers seem the model of Americanism with their small-town upbringing, unflagging work ethic and self-taught knowledge. While he mentions their quirks and foibles, he finds their characters elusive.

Instead of melding their words into his narrative, McCullough quotes large chunks of material, some of it newspaper hyperbole and exaggeration. He doesn't question the Wrights' behavior or speculate on their singular natures, preferring to allow their words, not his, to describe them.

Despite their old-fashioned manners and plain style, the Wright brothers were reticent and difficult people, traits that McCullough seemed unwilling to explore in his search for the virtues and strengths he values so much in American life.

Bob Hoover is the retired book editor of the Pittsburgh Post-Gazette.