The symbol has increasingly come under fire as glorifying of anti-Black bigotry and white supremacy.
At least 10 images of Confederate battle flags with cotton plants stuck to them were put up around American University in Washington on Tuesday in apparent protest of the school's new anti-racist research center.
Campus police circulated images and videos on Wednesday of a white man wearing a yellow fluorescent vest and an orange hard hat, saying he was suspected of defacing school property by pinning the flag posters to various noticeboards around campus.
The posters appeared the same evening as a talk about the school's new Anti-Racist Research and Policy Center by its founding director, Ibram X. Kendi.
Sylvia Burwell, the university's president, said she was angered to learn of the posters after leaving Kendi's talk. "When one of us is attacked, all of us are attacked," she said in a statement.
The Confederate battle flag was an emblem of the pro-slavery Southern states during the 1861-1865 Civil War.
Following the 2015 white terrorist attack on an African Methodist Episcopalian church in Charleston, South Carolina, that claimed nine lives, the symbol has increasingly come under fire as glorifying of anti-Black bigotry and white supremacy.
There have been widespread demonstrations and rallies across the United States in recent months over Confederate monuments and symbols, notably in Charlottesville, Virginia, where a woman was killed during clashes between white supremacists and anti-racist protesters.
Many white U.S. residents, including President Donald Trump, claim that symbols of the Confederacy must remain in public view as a reminder of the country's history.
For decades following the Confederacy's defeat, a nostalgic myth of the so-called “Lost Cause” — noble Southern “rebels” rising up despite the odds to defend their way of life from federal government overreach — proliferated across the U.S. south among white people.
This revisionist history laid the basis for the rise of white terrorist groups like the Ku Klux Klan as well as Jim Crow segregation laws that systematized the continued oppression and exclusion of Black people.