Walden, a game

You can do this achievement on the same playthrough you are using for the Hermit achievement. However, you must wait until after you have received the Hermit achievement to unlock this one as this requires you to go into Concord.

If you go to the General Store in Concord, and you go over to the household tab, you will see you have an option to pay back taxes. This costs $9. What I did was make a save before paying, because if you pay back taxes, you are locked out of the Activist achievement, which requires you NOT to pay taxes so you get thrown in jail. I was also going for the Walden Millionaire achievement so I didn't want to lose my money either. After paying taxes, revert back to the previous save you made so you are not locked out of the Activist achievement.