The Allen Memorial Art Museum's collection of 20th-century art is one of the finest of any undergraduate academic institution in the United States. This collection, which includes examples from almost every major modern artistic movement, has been assembled through a combination of patron generosity, curatorial acumen, and a certain amount of pure serendipity. Now one of the great collections held by the museum, the slow formation of the 20th-century holdings illustrates the sustained interest by the museum in collecting art from the artistic vanguard of the past century.

For the first several decades after the museum opened in 1917, very few works of art from the 20th century were accessioned into the collection. During that period, the growth of the collection was concentrated on the areas of Asian and earlier European art. Only in the 1930s did the museum begin to acquire examples of contemporary art, mainly prints that reflected the progressive tastes of that era. During the 1940s, this interest in collecting modern works on paper expanded with acquisitions in varying styles, ranging from a modernist watercolor by John Marin to animation stills from the Walt Disney Studio’s movie, Pinocchio. With the support of the R.T. Miller, Jr. Fund, the museum purchased several important modern works in that decade, including paintings and drawings by Paul Klee, Käthe Kollwitz, and Pablo Picasso.

The 1950s were a golden era for acquiring works of the artistic vanguard, and during those years the AMAM accessioned some of its best-known paintings, such as Ernst Ludwig Kirchner's Self-Portrait as a Soldier and Arshile Gorky's The Plough and the Song. Nineteen fifty-five saw the beginning of a series of donations of important 20th-century art from Joseph and Enid Bissett, whose nephew, J. R. Judson, had attended Oberlin in the 1940s. From 1955 to 1966, the Bissetts gave a total of 24 paintings, including two paintings each by Marc Chagall and Amedeo Modigliani, and seven paintings by Jean Dubuffet.

With the arrival at Oberlin College of Ellen Johnson, a professor of art history, the collecting focus shifted to include contemporary American art. Not only did Johnson secure purchases of artwork by emerging artists (such as Richard Diebenkorn's Woman by a Large Window in 1958), she also established close relationships with artists like Claes Oldenburg, Andy Warhol, Frank Stella, Eva Hesse, and Jim Dine. During the 1960s and 1970s, Johnson nurtured a committed group of students and patrons, most notably Ruth Roush and Annalee Newman, who ensured the expansion of the contemporary collection. By the late 1970s, the collection of modern and contemporary art had grown to such an extent that the college commissioned the architectural firm of Venturi, Scott Brown to build an additional gallery for contemporary art, and named it in Johnson’s honor.

The AMAM began to develop its collection of photography only in the early 1970s; it now includes multiple works by Edward Steichen, Diane Arbus, Cindy Sherman, and Robert Mapplethorpe. The prints and drawings collection has also continued to grow, and in addition to many masterworks it includes over two hundred drawings by Eva Hesse, given by the artist’s sister, Helen Hesse Charash.

The AMAM's collection of 20th-century art was formed over many years through the vision of numerous curators, including Ellen Johnson (honorary curator), Chloe Hamilton Young, Athena Tacha, William Olander, Stephen McGough, Elizabeth Brown, Lucinda Barnes, Amy Kurlander, and Goran Tomcic. Recently, the AMAM has continued to build its collection of 20th-century art with particular emphasis on contemporary Asian and African-American art.