Take a gander at Robert Cornelius. Source

Depends on what you're willing to take as "exactly what they looked like".

The Tolland Man and La Doncella have incredibly preserved faces and predate any photography and even advanced painting techniques.

How would reconstruction not be exactly?

Could you explain what you mean?

Are you basically asking who the first person photographed was? It's unclear what you mean by "exact".

This question really depends on your definition of 'exactly' and 'reconstruction'. If you have someone's skull you can use facial analysis to get a very good idea of what they looked like. Using this definition you could find human remains that are over 100,000 years old.

If that's too far of a stretch you could look to the oldest preserved complete bodies. The Tollhund Man is an incredibly well preserved natural mummy from ~2400 years ago. His face is so well preserved that by any definition this counts as knowing exactly what he looked like.

Edit: wrong date

I'm removing this. It is attracting very small, trivia-like answers. Without more explanation from the OP (which he/she has not provided) this question is essentially unanswerable. To prevent a further attraction of trivia, I'm taking this down now.