One attendee, who is white, wore a sign bearing the words "Black America I'm Sorry!!" as she walked up to Alton's casket to say goodbye.
For the family, though, it was simply an opportunity to mourn their loved one's death and say goodbye to him one last time before his body is put to rest.
Luminaries including the Rev. Jesse Jackson and close family members spoke about Sterling, his death and the police treatment of African-Americans.
Meanwhile, a man involved in what police have described as a credible threat to harm police officers is expected in court Friday.
Speakers at Alton Sterling's funeral are calling for justice in the shooting death of the 37-year-old black man at the hands of two white police officers.
A Baton Rouge man's bond on a 2015 sex-crime charge was revoked this week following his Sund... But they used deadly force after Sterling reached for a gun in his trousers pocket, it said.
A public viewing is set to begin at 8 a.m. CDT at Southern University in Baton Rouge followed by a funeral.
We've obtained the East Baton Rouge District Attorney's full statement regarding his decision to decline prosecution of about 100 protesters arrested during demonstrations following the shooting death of Alton Sterling. "'If you want to protest please leave now, ' he told the crowd, after noting that the ceremony was meant to be a celebration of Alton's life instead of a protest of his death". About 200 protesters were arrested over the weekend and police said they had foiled an alleged plot to attack officers.
Among those who will not be prosecuted is DeRay Mckesson, a leading figure in the call for police reform who has risen to national prominence with the increasing visibility of the Black Lives Matter movement.
One of the biggest rounds of applause from the crowd of about 2,000 came for Abdullah Muflahi, who owns the Triple S. Mr Muflahi said Mr Sterling was not just a man who sold CDs in front of his store.
The American Civil Liberties Union of Louisiana had filed a lawsuit earlier this week over police treatment of protesters. "He was truly the meaning of southern hospitality", Mr Muflahi said.
Moore said his office is reviewing the other cases, which include allegations such as resisting arrest, carrying guns or some "act of violence". A day after Sterling's death, Philando Castile was shot and killed by a police officer in Minnesota during a traffic stop with his girlfriend streaming the aftermath of the black man's death live in Facebook.