Gold had been found at various places in California before James Marshall made his now-fabled discovery in January 1848 near the sawmill he was building for businessman John Sutter. But coming as it did in the same year that America took California from Mexico, Marshall's far richer find was pivotal in changing the course of national history. Fueled by the ambitions and needs of hordes of fortune-seekers, the territory would, within the next two years, be admitted into the Union as a "free" state, thereby heating up the political pot that ultimately exploded into the Civil War.

In The Age of Gold: The California Gold Rush and the New American Dream, historian H.W. Brands examines these whirlwind developments through accounts left by those who took part in them. After setting the scene of the discovery and explaining how word of it spread around the world, Brands follows the individual progress of a handful of pilgrims as they travel overland or by ship to this 19th century El Dorado. He then demonstrates how the bustling region proceeded to cast its shadow over the rest of the country.

Chronicling an entire epoch was a new experience for Brands, a Pulitzer Prize nominee who teaches American history at Texas A&M University. "I had recently done a couple of biographies," he says, "and when you do a biography, especially the way I do it as a life and times you get a long but rather narrow slice of history. For example, I did a biography of Benjamin Franklin [The First American]. His life spanned almost the entire 18th century, with the result that, in tracing his life, I could trace the course of American history over nearly a century. But because I focused on one person, I tended to get a rather narrow view of that history. What I wanted was a different approach. In choosing the California gold rush, what I did was turn that window of history on its side, so that instead of being long and narrow, it was very wide but rather short. Instead of looking at 84 years the term of Franklin's life through one person, I looked at eight or 10 years through the eyes of the dozen or so people I focused on. This is the way of getting at an event as opposed to getting at a life."

Brands, whose other biography is T.R., a life of Theodore Roosevelt, says he spent about five years researching and writing The Age of Gold. "My interest in the gold rush began when I was in college," he explains. "I grew up in Portland, Oregon, and went to college in California. I had occasion then to travel around in the gold country of the Sierra Mountains. I was intrigued by it, and I've always had this notion to come back to that area and that subject."

Among the figures Brands accompanies on their arduous treks to the gold fields are Jessie Fremont, daughter of Missouri senator Thomas Hart Benton and wife of California settler John Fremont, and Sarah Royce, who would become the mother of philosopher Josiah Royce.

Brands' descriptions of the parched landscape and daily privations that nearly took Mrs. Royce's life are especially vivid. "Before I was a historian," Brands says, "I spent a while as a traveling salesman. My territory was from the West Coast to Denver. So I drove along all the Humboldt River and over Immigrant Pass, east of Salt Lake City, across the Great Salt Desert and along large stretches of the Oregon and California Trails. Of course, you don't see it exactly as it looked in 1849, although I will say this, there are big sections of that part of the West where, if you just turn your back to the interstate or whatever paved road you're on, it looks a lot like it did 150 years ago." Because the gold attracted such an array of talents, energies and egos, it fostered a can-do attitude and an impatience with the status quo that, Brands argues, remains a part of the California character to this day. In his estimation, the gold rush was not a manifestation of greed. "Greed is what you call it if you think it's not deserved or it's excessive," he contends. "People who went to California didn't consider themselves greedy. They saw that this was an opportunity to improve their lives. Most of the people didn't think they were going to make $10 million. They would have been quite happy to make $500 or $1,000 enough so they could buy a farm, for example, rather than rent a farm, so that they would have enough money to marry their childhood sweetheart, so that they could start the business they wanted to start. For most of them, it was this opportunity to make a shortcut toward their vision of happiness."

Brands admits that his study of history has shaped his own political outlook: "I think it gives me greater tolerance for the fact that we always seem to muddle through, one way or another. There have been dozens of moments in American history where it looked as though we were in a crisis that the country might not survive and that some big decision had to be made and if it wasn't made right, then the entire American republican experiment would come tumbling down. Despite all of those grim warnings, the Republic still carries on. . . . There are these things [like the September 11 terrorist attacks] that pop up, and at the moment they seem to be the most important things one could imagine. It's easy to think and sometimes it's attractive to think that we live at this turning point in history, because it confers a certain kind of importance on us."

Brands' manuscript for his new book was already in the hands of his publisher when the stories broke about the alleged plagiarisms by fellow historians Stephen E. Ambrose and Doris Kearns Goodwin. Even in light of this news, he says his publisher did not ask him to re-check his own work. "It's had a lot of reverberations in the historical community," he notes. "It comes down to a question of whether these were matters of simple oversight, or sloppiness or intent to deceive, and professional historians have taken different views. It's hard to say where the truth lies, but I think we all try to do the best job we can." Next up for Brands will be a book on the Texas Revolution of the 1830s.