US civil war historians

[Dartagnan]

I'm looking for a list of historians and their works specialising in the civil war era.
Typically the topics I need to cover are the build up to war, war events, and consequences.
Mainly focussing on politics rather than economics or tactics.

If at all possible, I'd like 2 from the time, writing their first hand accounts, 2 from a later period, and 2 modern.
Extra points if they have extremely conflicting opinions.

On top of that, I need primary source material, so if anyone knows where I can find letters of Lincoln/Lee or any other figures that would be extremely helpful.

+rep to those who help
Thanks.

[Flavius Nevitta]

Good and interesting books I recently read are:

Robertson, James I. Jr.:"Stonewall Jackson"

and

Burke Davis: Gray Fox : Robert E. Lee and the Civil War

For 1st hand accounts I'd read:

Edward Porter Alexander: "Fighting for the Confederacy"; (imho the best written and objective 1st hand account I've read so far)

there was another request here with many very good recomendations:
here

hope this helps