If you have been convicted of a felony, are on probation, or on parole, your state may prevent you from registering to vote. The laws differ from state to state, but 48 states and the District of Columbia restrict voting for felons in some way or another. According to the National Campaign for Fair Elections, 4.7 million Americans are disenfranchised because of felony convictions. Some of these people are prevented from voting by law; others are held back by red tape and local barriers.
If you are struggling to find a way to vote while holding a criminal record, educate yourself on the laws. You might find you have more rights than your realize. You can learn more about the laws in your state here. Or you can visit The Sentencing Project to learn more about the Right to Vote campaign.