How do I get more politically active in socialism/democracy in America?

I am a 24 year old white male from Indiana. I lived in England for 2 years and in Africa for 1. I have seen some of the most politically active people and I have seen a collective whole of people strive to ensure their rights in those countries. What I see in America makes me so sad. Our country is not democratic, but ran by the wealthy. I see a rapid spiral occurring in which, I fear, there will soon be no return from. Being from one of the smallest towns in the country, how can I step up and fulfill my patriotic duty to ensure that America remains for the people?