“To me, a noose is lynching,” said Taylor Dumpson, who is the first black woman to become president of American University’s student government. “That’s immediately what comes to my mind, that someone is going to hang you, that someone is going to die. That’s a very chilling thing.”
Nooses have also been found in recent months at a middle school in Florida, at a high school in North Carolina and at a fraternity house at the University of Maryland. Also in Maryland, two 19-year-olds are being prosecuted in the hanging of a noose from a light fixture outside a middle school.
At the same time, members of the Ku Klux Klan — an organization whose history is closely enmeshed with the use of nooses in lynchings — appear to be stepping up their public activities. Robed Klansmen appeared at a gay pride march in Florence, Ala., last month, and the Loyal White Knights of the Ku Klux Klan are planning a rally in Charlottesville, Va., on Saturday.
The noose at the Mint was particularly shocking, Ms. Sapp said, because the facility is under heavy surveillance given its security concerns — employees know they are being recorded as they work. After a daylong investigation, during which the creator of the noose was kept off the factory floor to protect him from physical retaliation, Ms. Sapp said he was placed on administrative leave on Thursday and escorted out of the building.
But she said that Treasury officials had not done enough to address the roots of persistent racial discord within the factory, adding, “They sweep a lot under the rug.”
The Treasury spokeswoman said only that Treasury Secretary Steven Mnuchin had “directed that this matter be handled swiftly and seriously.’’
Advocacy groups who track hate crimes say the rash of noose cases is part of an uptick in hate crimes, fueled by the coarsening of public conversation that began during last year’s presidential campaign, and has continued amid bitter divisions over the election outcome.
“We are in a moment right now where we certainly have not only heightened awareness, but a greater frequency of hate incidents,” said Jonathan Greenblatt, chief executive of the Anti-Defamation League, which monitors hate crimes. He called the surge in noose episodes “really alarming.”
The hangman’s rope has been used for centuries to execute people, but became a particular object of racial terror in the United States during the late 19th and early 20th centuries, when 4,700 people — mostly men but also women and children — were hanged from trees, telephone poles and bridges across the nation, according to Jack Shuler, the author of “The Thirteenth Turn: A History of the Noose.’’ Roughly three-quarters were African-American.
As to why nooses are appearing with increasing frequency today, Mr. Shuler said: “That’s the $64,000 question. I think we’re in a historical moment where people feel like they have permission to be hateful.”
Current data on nooses, though, is difficult to come by. The F.B.I. — which is investigating the American University case as a potential hate crime — keeps figures on such crimes; its latest report, released in November, showed a 6.7 percent rise in reported hate crimes in 2015, the most recent year for which figures are available.
A study of law enforcement and government agencies’ data in 25 metropolitan areas, conducted by the Center for the Study of Hate and Extremism at California State University in San Bernardino, showed the number of hate crimes jumped to 1,988 in 2016 from 1,886 in 2015 — an increase of 5.4 percent.
The Southern Poverty Law Center says it has documented 1,863 episodes of bias since the day after the presidential election; of those, 292, or nearly 16 percent, were aimed at African-Americans. “One of the most pervasive manifestations of these happenings is the display of nooses,” the center wrote in a blog post published last month.
One of the most troubling instances involved a noose at a display about segregation in the National Museum of African American History and Culture, which has become a popular tourist destination here since its opening last fall. The rope was found in late May, in an exhibit chronicling America’s evolution from the era of segregationist Jim Crow laws through the civil rights movement.
Several of the recent noose cases appear to be aimed at specific people. At Wakefield High School in North Raleigh, N.C., someone hanged a black teddy bear from the roof, with a message aimed at the principal, Malik Bazzell, who is black. Beside the doll was a sign saying, “Make Wakefield Tripp again.”
The Raleigh News & Observer reported that the sign referred to Tripp Crayton, the white former principal, whom Mr. Bazzell replaced in 2015. Mr. Bazzell called it a ‘‘deeply offensive act.’’ Four high school seniors were later arrested and charged with trespassing and damaging school property.
At American University here, the bananas hanging from nooses seemed clearly aimed at Ms. Dumpson, 21,. Some of the bananas were painted in black with the words “Harambe Bait,” a reference to the gorilla at the Cincinnati Zoo that was killed after a child fell into its enclosure in 2016. Others said “AKA Free,” an apparent reference to Alpha Kappa Alpha, a black sorority to which Ms. Dumpson belongs.
Ms. Dumpson said she grew up knowing the powerful symbolism of the noose. She was raised on the Eastern Shore of Maryland, a region that aligned itself with the South during the Civil War and where racial tensions run deep. Lynchings took place near her hometown, Salisbury, as recently as 1933, she said.
She was on the subway, traveling to school, on May 1 when she got a Facebook message from a friend showing her pictures of the nooses on campus.
“My stomach just dropped,” she said. “I knew what a noose was, I knew the history, just as much as I knew the history of the Confederate flag. Those were things I was taught to recognize.”