The pleas came from community leaders who promised to reconnect with the predominantly black community in the Missouri suburb.
They asked residents to stay home at night to "allow peace to settle in" following the shooting of Michael Brown by a white police officer and Tuesday night was more peaceful.
US Attorney General Eric Holder visited Ferguson yesterday to be briefed on the progress of a separate civil rights investigation he has ordered into Mr Brown's killing.
In a message to the community, Mr Holder said about 40 FBI agents have been assigned to the case, along with prosecutors in the US Attorney's Office, and that hundreds of people have already been interviewed.
An independent autopsy, the third conducted in the killing, has also been performed by federal medical examiners at Mr Holder's direction.
Mr Holder said: "Our investigation into this matter will be full, it will be fair, and it will be independent."
He joined Governor Jay Nixon and other officials in a renewed appeal for public calm following demonstrations that have gripped Ferguson almost every night since Mr Brown was killed.
The officer who shot him has been placed on leave and gone into seclusion, while Mr Brown's family and their supporters called for his arrest.
The National Guard arrived in Ferguson earlier this week but kept its distance from the streets on Tuesday night.
Benjamin Crump, a lawyer for Mr Brown's family, said the teenager's funeral and memorial service would be on Monday.
Meanwhile, a large crowd gathered in nearby St Louis on Tuesday afternoon after officers responding to a report of a store robbery shot and killed a knife-wielding black man. Police Chief Sam Dotson said the suspect acted erratically and told responding officers to "shoot me now, kill me now".