BOULDER, Colo. (AP) – Elizabeth Fenn, an associate professor of ethnic studies at the University of Colorado at Boulder, was working in her office Monday when she learned that she had won the Pulitzer Prize in history.

“I’m still processing it,” Fenn said in a telephone interview. “I’m just so pleased that the Mandans are getting the historical recognition they are due.”

Fenn’s book, “Encounters at the Heart of the World: A History of the Mandan People,” profiles the group that lives in what today is North Dakota, and among whom the Lewis and Clark expedition camped in its first winter of 1804-1805. The Mandans numbered about 15,000 in the year 1500, Fenn said, and her work profiles them through a terrible smallpox epidemic in 1837-38 and up to the year 1845.

“My pitch is that stories like this need to be a part of the early American canon,” Fenn said. “We need to think of early America as far bigger and more interesting than the 13 English colonies, or the Russian colonies, the Spanish colonies and the French colonies.”

Fenn, whose work focuses on the American West and Native American history, has a Ph.D. and a master’s degree in history from Yale University and a bachelor’s degree in history from Duke University.

Asked about the Pulitzer’s significance, Fenn said it should help the Mandans’ story “become part of the American canon.”

“They’re getting their due in American history,” she said, shortly before teaching a graduate research class on American frontiers.

The Pulitzers, established by newspaper publisher Joseph Pulitzer and first given out in 1917, are American journalism’s highest honor. They recognize various categories of reporting, photography and opinion writing, as well as editorial cartooning.

The prizes also honor drama, music and fiction and non-fiction books.

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