The Allen University Historic District covers Arnett Hall, the Chappelle Administration Building, Coppin Hall, the Joseph Simon Flippen Library, and the Canteen Building. Together they are listed on the National Register of Historic Places, added April 14, 1975, and they also fall inside the Waverly Protection Area within Columbia's local preservation system. The campus reads as a coherent Classical Revival ensemble - red brick, white columns, restrained pediments - because that vocabulary was the vocabulary of American public dignity in the late nineteenth century. Building in that style was a deliberate claim: a Black university in the post-Reconstruction South was entitled to look as serious as any other American institution of higher learning, and it would.

The centerpiece of the district is the Chappelle Administration Building, which is also a National Historic Landmark in its own right - one of relatively few structures in South Carolina to carry that highest designation. It was designed by John Anderson Lankford, an architect educated at Tuskegee Institute and Shaw University, known as the Dean of Black Architects, who served as the official architect of the AME Church and produced churches, schools, and lodges for Black congregations across the country at a time when most American firms refused them as clients. Inside Chappelle is a 700-seat auditorium where Mary McLeod Bethune, Martin Luther King Jr., Muhammad Ali, Jesse Jackson, and Langston Hughes have all spoken or performed. In 1944, educators and NAACP lawyers met in that auditorium to plan the strategy that became Brown v. Board of Education ten years later.

When the campus was laid out in the 1880s, this was the leafy edge of Columbia - the Waverly neighborhood, then a streetcar suburb whose Black middle class built churches, fraternal halls, and family homes along Harden, Gervais, and Hampton Streets. Downtown Columbia has since walked up to meet the campus, and Allen now sits within a short walk of the State House. The Waverly Historic District around it preserves the broader fabric: shotgun houses, Queen Anne cottages, and the businesses that served a community sustained for decades by deliberate self-organization. Walking through the district today, the four columns of Chappelle rise above the green like a quiet argument with anybody who ever doubted that Black Columbia could build its own institutions, on its own ground, on its own schedule.