ALL cities - indeed - ALL jurisdictions in the United States are patrolled by some type of law enforcement agency. Most large cities have their own established Police Departments but there are still some who are patrolled by Sheriff's Departments.
450 police departments
According to Wikipedia, there are 131 city police departments in Oregon.
There are a total of 141 police departments in the state of Florida. The largest of those is the Miami-Dade Police Department.
Police chief.
No. Many books and movies portray actual police departments.
if you mean how to become a police officer.. In most states in the US you have to be 21, legal US citizen, pass a criminal background check, and pass the departments academy. i cant be sure but some states or departments might require some sort of military experience or higher education ,
contrasting the roles and functions of municipal and county police departments
Most police departments do post job opportunities online. Job listings for police departments can typically be found on the city's website and include requirements of the position and instructions for how to apply.
More information about a police academy may be obtained by contacting local police departments. Local police departments will have information about training requirements.
The US Bureau of Justice Statistics regularly issues a statistical report on Local Police Departments. The most recent report was issued in 2003. As of 2003 there were more police agencies with 10-24 officers, 30 percent, than any other size.
There are a multitude of agencies that fight crime in the US. They range from local police departments to county sheriffs to state police to national agencies like the FBI.
Not all police departments are the same. Some departments let ranks as low as corporals become detectives, while some departments only allow lieutenants and captains. Regarding police, I have no idea what a "level" is