How long have counties been a part of the government structure of the united states?

How did the country form or government develop?how long did the counties been a part of the government structure of the USA?
The way that the county form of the government developed was by responding to emergencies, law enforcement,paving and repairing roads, creating and managing parks,and making sure we all have clean water to drink. Counties have also been a part of the government structure of the USA since 188.

The dangers of an inadequate monetary supply.