Martina McBride is the biggest name to drop out of the festival, which is being held to celebrate the 250th anniversary of the United States' Declaration of Independence. She says she was assured the event would be non-political.
"But yesterday there was a change and we have been told that this is not actually the case," the country star writes on social media.
Young MC, Morris Day and the Commodores are also canceling their performances. Some of the big names that will be at the festival include Flo Rida, Vanilla Ice and Milli Vanilli.
"I'm here to entertain and unite people, not to create division," Fab Morvan of Milli Vanilli told The Guardian.
