A--the secret ballot was added to keep pressures from corrupt political machines off of voters. Imagine you're going to vote in a non-secret ballot--the person recording your vote can clearly see your choice. In political machines, it was common practice to bribe voters for support in elections. If that person collecting your vote happens to work for a political machine (which, before the start of the Progressive Era, was common), then they will probably let their boss know if you did or did not vote for them, giving political machines the power to reward those who voted for them and punish those who didn't. Therefore, many voters were frightened into voting for political machines. The secret ballot took away this power, so the people were able to vote for whomever they'd like without fear of punishment.
