The Memorial Union and Terrace, an iconic building on campus for generations of University students and visitors, was constructed in 1926-1928. Designed in the Italian Renaissance Revival style, the Union exudes stately elegance. The Terrace, a lakeside patio, quickly became the premier social center of the University of Wisconsin, a role it still plays. In 1928-39 a theater wing was constructed in the International style. The interior of the Union features grand public spaces decorated with a variety of elegant finishes including stained wood, marble, ornamental plaster, tile, and painted murals, with some rooms featuring classical colonnades, fireplaces, and coffered ceilings.

The Memorial Union is nationally significant in the American college union movement, which in the historical Progressive era, was an undertaking to provide a social and recreational gathering space for all students, breaking down class and socioeconomic barriers. Progressive education supported the development of the whole student, socially, emotionally, and physically as well as academically, and encouraged each student to use what he or she had learned for the greater good, as a citizen contributing to our democratic society. The University of Wisconsin was on the leading edge of this Progressive initiative and went so far as to give students leading roles in governing and cooperatively managing programming, and physical changes to the building.

The University of Wisconsin Memorial Union is also significant for its association with Porter Butts (1903-1991), and his work as Director of the Wisconsin Union from 1928 until 1968. Butts was the driving force guiding the evolution of the Wisconsin Union to fulfill the ideal of Progressive education, exemplifying the potential of college unions and continuing to expand that definition through innovative academic programs, and scholarly research and publishing.