The protest was billed as a "Shut Down Trump and the RNC" rally but those gathered also spoke out against police brutality.
Protester Monica Moorehead urged people to "continue being in the streets, shutting down interstates and highways and malls" to draw attention to the issue, the Telegraph reported.
Law enforcement prepared for huge demonstrations in the coming days during the convention, with a third of Cleveland’s 1,500 police officers alongside more than 2,000 officers from departments around the country deployed.
Security across Cleveland's downtown area was fortified with barriers and thousands of additional security personnel.
Convention CEO Jeff Larson said officials are supportive of anyone executing First Amendment rights as long as they do it "in an orderly fashion."
He said police are prepared to move in and take action if any demonstrations get disorderly. But he said he "feels good" about the security preparations in place.