He was born to privilege and sought the world of art. She lived at the center of that world-a working artist encouraged by the famous artists in her extended family. Together, Duncan Phillips and Marjorie Acker Phillips founded The Phillips Collection in Washington, D.C., the first museum of modern art in America. It opened in the grand Phillips family home in 1921, eight years before New York City's Museum of Modern Art and only a few weeks after they wed.

Duncan took the lead in developing the collection and showcasing it. Marjorie kept space and time to paint. Duncan considered Marjorie a partner in the museum even though she was not directly involved in all purchasing and presentation decisions. To him, her influence was omnipresent. Although Duncan's writings on artists and art history were widely published, he chose not to provide much instruction for visitors to the museum. Instead, he combined signature methods of displaying art which live on at The Phillips Collection. Phillips had viewers in mind when he hung American art with European art-or art of the past with modern art, and he frequently rearranged works to stimulate fresh encounters.

With unfettered access to archival material, author Pamela Carter-Birken argues that The Phillips Collection's relevancy comes from Duncan Phillips's commitment to providing optimal conditions for personal exploration of art. In-depth collecting of certain artists was one of Phillips's methods of encouraging independent thinking in viewers. Paintings by Pierre Bonnard, Arthur Dove, Georgia O'Keeffe, John Marin, Jacob Lawrence, and Mark Rothko provide testament to the power of America's first museum of modern art.