I have created four characters that I want to add to my current campaign.  I don't see a way to move them over.  Do I have to re-create them in the campaign?

You need to go to the campaign link then you can choose a character you have created to use.

Then unassign the character to you, rinse and repeat

Quote from sardonicmonkey >>

You need to go to the campaign link then you can choose a character you have created to use.

Then unassign the character to you, rinse and repeat

 Actually, only unassign them if you want your players to be able to claim it. If you want them as NPCs then keep them claimed. You can have as many claimed PCs in your own campaign as you want I believe. I have more than 20 in one campaign.

Thank you for your feedback, that worked.