This collection initially focused almost exclusively on the Vandenberg Center Sculpture Project, which resulted in the acquisition of Alexander Calder’s monumental stabile La Grande Vitesse. Additional materials, about Nancy Mulnix continuing and broader activities in support of the arts, have been added to the collection, broadening the scope of the collection.

Calder’s La Grande Vitesse continues to be the largest portion and the hallmark of the collection, and perhaps Mulnix's greatest art experience. The Vandenberg Center project materials detail how politicians, artists, business leaders and private citizens joined to acquire La Grande Vitesse during an age of urban renewal and city reidentification in Grand Rapids. This was also a time of national political upheaval in the late 1960’s, which included civil rights at the forefront and the assassinations of important political leaders in the U.S. These national issues struggled against the Calder project for recognition and use of resources. However, the ideals of both movements seemed to come together in the human rights ideals of the Calders (Alexander, or Sandy, & Louisa), as well as the ideals of the use of the Vandenberg Center plaza, now called Calder Plaza, as a meeting place for all peoples and all groups, with La Grande Vitesse as the focal point. It was also an era of global reidentification, as the first man was landed on the Moon in the month following the dedication of the sculpture.

Mulnix served as co-chairman of the Vandenberg Center Sculpture Committee along with Grand Rapids leader Peter Wege. The collection includes her correspondence as part of the Committee. Prominent correspondents in the collection include: Alexander Calder, artist Adolph Gottlieb, Aaron Copland who wrote original music for the Dedication of the sculpture, and Gerald Ford, who as President used “La Grande Vitesse,” as part of his symbolic association with his home city of Grand Rapids.

The collection also includes records of the art Selection Committee / Commissioning Committee, speeches, Calder sketches, clippings, memorabilia, ephemera, photographs, slides, prints, posters, audio tapes, musical scores and engineering plans. A large portion of the collection is books and periodicals, either on Calder and his art, or on public art and art projects. These materials serve as an invaluable support for understanding the sculpture, as well as it’s creator and it’s place in U.S. national history, as the first public sculpture supported with federal funds.

The collection also includes material on Calder’s other works and exhibits. The personal friendship that existed between Mulnix and Calder provides an interesting dimension to the collection, as well as her other friendships with such notables as Inge Morath Miller and her husband Arthur Miller, Eppie Lederer (Ann Landers), Aaron Copland who knew Calder as a youth in Pennsylvania, Calder’s official biographer Jean Lipman, Calder friend Robert Osborn, and Calder’s sister Margaret Calder Hayes. Also included are brief notes from Jane Alexander, actress and chairman of the NEA in 1994, from artist Robert Motherwell, from Kansas Senator Nancy Landen Kassebaum, from Chief Justice William Renquist and Justice John Paul Stevens of the U.S. Supreme Court, and from Michigan Governor William Milliken, plus a copy of a telegram from President Richard Nixon with congratulations on the dedication of the sculpture.