The Obama Presidential Center construction in Chicago has been put on hold after noose was found there.
The project’s backers, the Lakeside Alliance, a collection of Black-owned construction firms, claimed to have reported the incident to police on Thursday.
To find the offenders, they are offering a $100,000 (£85,000) prize.
The incident was referred to as a ‘shameless act of cowardice and hate’ by the Obama Foundation, the former president’s non-profit organisation, in a statement.
The statement read, ‘Protecting the health and safety of our personnel is our priority.’
JB Pritzker, the governor of Illinois, also denounced the event, tweeting that ‘the noose is more than a symbol of prejudice.’
According to Mr. Pritzker, it is a ‘heart-stopping reminder of the murder and terror imposed on African Americans for decades.’
Construction on the project has been suspended, according to the company in charge, so that workers and staff can get anti-bias training.
According to a statement from Lakeside Alliance, ‘We have zero tolerance for any type of intolerance or hate on our workforce.’
The extrajudicial hangings or lynchings of mostly black persons in the United States in the late 19th and early 20th Centuries are associated with the looped rope.
Barack Obama and his wife Michelle attended a groundbreaking ceremony for the Center last September, and construction on it will start in 2021.
The $500 million (£424.3 million) Center is scheduled to open in 2025 and anticipates 750,000 visitors annually.
The Center ‘represents a historic opportunity to establish a world-class museum and public gathering space that celebrates our nation’s first African American President and First Lady on the South Side of Chicago,’ says the Obama Foundation’s website.
Private donations accounted for the majority of the cost of construction.