Yet another design question 1

[up2late]

object:
I have agents working across 3 States. Each agent covers more than one county. I started by setting up an agent table and a table for each state. The state tables have 2 fields, auto_increment and county name.
From reading some other posts here I think I've done this wrong. For best results I should have 1 table that tracks all the counties and add another field to it for state. So it would hold ID, county name, and state name. Does that sound like a better way to do it?
Second question is whats the best way to track (in the agent table) the several counties that each agent works? I know I should list the ID from the county table, but whats the best way to do that? Should I have a text field with the county IDs in it? Thats sounds like it would slow everything down.
Thank you for any advice you can give.
Dave

 

[TonyGroves]

The following tables should work:

Agents:
Agent code (PK)
Agent name
any other info

Agent_assignments (one record for each county assigned to an agent):
Agent code (PK)
State code (PK)
County code (PK)
any other info

Counties:
State code (PK)
County code (PK)
County name

States:
State code (PK)
State name

 

[up2late]

Thank you for the quick reply and advice. I'll start reworking it tonight.