(CNN) A noose. It's simply the loop at the end of a rope, under a running knot, which tightens as it's pulled. And yet it has the power to spur shivers of terror.
In America, the hangman's noose has come to symbolize a deplorable act of brutality, along with unbound fear and hatred towards African Americans. It's a reminder of America's dark history of racial violence -- a history that NASCAR driver Bubba Wallace and others will tell you in 2020 doesn't feel very distant at all.
"The noose always means much more than a knot in a rope," said Jack Shuler, an associate professor at Denison University and author of "The Thirteenth Turn: A History of the Noose."
"The noose was a tool used to kill people and, therefore, it is a threat -- it is violent speech," Shuler added. The noose has become the new burning cross."
Here's why a noose has the power to frighten people -- and how it's still being used today as a symbol of hate.
The NAACP estimates that more than 4,700 people were lynched in the US between 1882 and 1968, although Shuler believes the number is probably much higher. Almost 73% of them were Black.
Most of the racial lynchings took place in the South, where many whites felt threatened by Black peoples' newfound freedoms and sought to intimidate and control them. Black men were strung up from trees, beaten to death or otherwise lynched for any number of alleged minor crimes.
These lynchings weren't even considered murders, according to Shuler.
"Lynching is not the same as private murder. It means an extrajudicial killing for an alleged crime by three or more persons," Shuler told CNN. "There must be some evidence that a community supported the act -- either actively or through their collective inaction."
Hate groups like the Ku Klux Klan were behind many of the killings. But in some places, entire communities would gather to watch Blacks being tortured and hanged, Shuler said.
"Though most often associated with being hanged by a noose, lynching also involved victims being tortured to death, burned alive, or riddled with bullet holes," he said. "Typically, the victim was hanged and then the body was mutilated."
Lynchings in the US subsided by the late 1960s. But as a vestige of that shameful era, the noose lives on.
The intention behind using a noose is crystal clear.
"If you knew anything about the history of American lynching," Shuler said, "then you wouldn't tie that knot without doing so for the expressed person of threatening another person."
In recent years, nooses have been found hanging outside the National Museum of African-American History and Culture in Washington, on college campuses and on a fence at an Oakland, California, elementary school.
And whether they realize it or not, every time a person ties a noose and hangs it they are sending a message.
"People who make these nooses know what it represents because it's historical," said Darryl "King Rick" Farmer II, leader of the Black Panthers of Milwaukee, where photos of six slain Black figures were found hung by nooses in a park over the weekend.
"Everyone knows what a hangman's noose represents, especially to the African American community. Either they've been living under a rock or they simply don't care."
On Sunday a noose was found in a Talladega garage stall used by Bubba Wallace, the only full-time Black driver in NASCAR's top circuit and an outspoken advocate of the Black Lives Matter movement. Days earlier, Wallace had spoken out against displaying the Confederate flag at NASCAR races.
(The FBI said in a statement Tuesday that the noose was hanging in the garage stall since as far back as October 2019 and that nobody could have known Wallace would be assigned that stall until last week.)
On Saturday, laminated cards showing photographs of Breonna Taylor, Eric Garner, Botham Jean, Ahmaud Arbery, Michael Brown and Trayvon Martin -- all Black people killed in encounters with law enforcement or private citizens -- were found hung by nooses from a tree in Milwaukee. The Milwaukee Sheriff's Office is investigating.
Last week what appeared to be several nooses were found hanging from trees in Oakland, California.
And these are just the most recent episodes.
In January, the only Black basketball player at a West Virginia high school found a drawing of a stick figure on a noose with his name. And in February, a 12-year-old girl at a Mardi Gras parade in Mississippi was given a black doll with beads forming a noose around its neck.
"It's important to remember that lynchings didn't end because Congress enacted laws to prevent them. Indeed, Congress never acted," Shuler said.
Bipartisan legislation to make lynching a federal crime, a long-sought goal of activists which got new momentum after the recent nationwide protests against police mistreatment of African Americans, is currently stalled in Congress.
Many White Americans can't comprehend the intensity of this felt history for African Americans, Shuler said.
"Lynching is a heinous and historical act that has been perpetrated against African American people. We are sensitive to nooses, we are sensitive to hatred, we are sensitive to the fact that systemic racism across America continues, and these nooses are a representation of that. We as African Americans are angry, appalled, upset, and we are fed up with it," said Farmer, the Black Panther leader.
"It brings back the terror, the disrespect," he added. "It brings back all the memories of crimes committed against our ancestors and to us until this day."