Premier Christy Clark helped announced "Solar Dance: Genius, Forgery, and the Crisis of Truth in the Modern Age" as the winner at a ceremony in Vancouver.
The book, which contains 56 short sections related to a Van Gogh work, beat out three other finalists for the honour.
Jury members Paul Whitney, Martin Levin and Jan Whitford called it a "fascinating work of cultural history, and a provocative analysis of the roots of the modern era as it developed in the social and political turmoil of the early 20th century."
The other shortlisted titles were George Bowering's "Pinboy: A Memoir," Robert R. Fowler's "A Season in Hell: My 130 Days in the Sahara with Al Qaeda," and Candace Savage's "A Geography of Blood: Unearthing Memory from a Prairie Landscape."
Eksteins is professor emeritus of history at the University of Toronto.
His "Solar Dance" was also recently a finalist for the $60,000 Hilary Weston Writers' Trust Prize for Nonfiction.