Alice Walton, the Walmart heiress, had her critics when she set out to open a major American art museum in remote Bentonville, Arkansas. But her 21-month-old institution has already welcomed its one millionth visitor and taken criticism to heart, rapidly expanding its collections in response to vocal opponents who perceived gaps.

In 2005 Walton shook up the New York art world with the puchase of Asher B. Durand’s seminal Hudson River School landscape “Kindred Spirits” from the New York Public Library for a rumored $35 million.

She has now focused on acquiring 20th-century artworks, with the help of her adviser John Wilmerding, to help round out her collections at the Crystal Bridges Museum of American Art.

One of her biggest coups will debut at the galleries this November: the modernist art collection formed by Alfred Stieglitz and given by Georgia O'Keeffe to Fisk University in 1949. Walton paid $30 million for a half-share in the Stieglitz Collection which includes four works by O'Keeffe. sHe gave Fisk a $1 million peace offering as well.