All good points. But in most democratic countries while you don't vote for the "chief surveillance officer" you vote for the person who is his boss (unlike say, here in the UK where you can only vote for your local representative). They ought to be able to push changes down from the top and have the ultimate executive power to help them do so.
(PS. I am not aware of the US Civil War (beyond the Ironclad battle) so I can not comment on that)
Well you might be aware that our federal government is divided into three branches. The President doesn't get to decide what the laws of the land are, that's up to Congress. So Congress creates a department, funds it, sets limits on it, and then the executive branch uses those funds to do the job. It get complicated, but to be specific, elections don't change laws. You would have to elect enough representatives to change the law, a president to sign the law, and then the courts would have to accept the law as constitutional.
(PS. I am not aware of the US Civil War (beyond the Ironclad battle) so I can not comment on that)