I was wondering if someone could help me out. I want to start getting more familiar with the genre. I am looking for artists similar to Howlin Wolf and Lightnin Hopkins (I know he is from Tx, but it is the same style pretty much). I'm looking for good slide guitars, minimalist production, the said musician has to be African American, and I prefer that atleast a few of the song themes be about slavery and prison if possible. I just started listening to a couple artists today, and I really like the atmosphere of it. Thanks i advance.

One more thing, if possible, I would like suggestions of whole albums. Greatest hits and random classic blues singles get hard to track down, and is really tedious shit to catalog.

Muddy Waters? Robert Johnson?

Blind Lemon Jefferson and Charlie Patton are really the only two guys i've checked out. Both are worth your time.

Seconded, and seconded.

Obviously.
P.S: Why not post this in the Recommendation Central?

I love a lot of blues music, and I can recommend a lot of performers, but for now I'll only recommend Buddy Guy and John Lee Hooker.
John Lee Hooker: http://www.youtube.com/watch?v=7GOCAC8FCqE
Buddy Guy: http://www.youtube.com/watch?v=D6tdlmx_GO4

I fucking LOVE Delta Blues, and you don't know how happy I am to see someone else actually has a desire to get into the music. I can't recommend albums because the little stuff I own are self made comps.
My personal favourites are:
Skip James: http://www.youtube.com/watch?v=OgcpuhvjNuw
RL Burnside: http://www.youtube.com/watch?v=K_DOnKJ232M
Son House: http://www.youtube.com/watch?v=jF7ie_erQH0
Blind Willie Johnson (Mostly gospel, but damn good gospel): http://www.youtube.com/watch?v=BNj2BXW852g
Not Delta by any means, but early Johnny Guitar Watson is a blues treat: http://www.youtube.com/watch?v=tVsNlchp0GE

Also, check out the RagtimeDorianHenry and AlanLomaxArchives pages on youtube. Lots of old times blues, as well all sorts of other old time music.

Well of course these are obvious ones. I am looking for artists that are a little lesser known.

Haha you should have mentioned in that in your OP! But yeah, I'm honestly not too familiar with the genre, I grew up listening to delta blues because it's all my Dad listened to besides Pink Floyd and Jimi Hendrix (he even used to have a dog named Robert Johnson), but he didn't listen to "underground" delta blues dudes or whatever, just the obvious stuff.

Junior Kimbrough is pretty badass. Dunno how obvious that is of a recommendation, but whatever - him and R.L. Burnside definitely get the most attention from me. http://www.youtube.com/watch?v=2tw0vMPXIxs Listen to "All Night Long" and all of his early recordings on "First Recordings." The Black Keys also did an entire album of covers of his songs, called Chulahoma, which is pretty cool.

That said, why do they have to be black? I mean, I think Eli Cook is really cool. Do yourself a favor and check him out even though he is white: http://www.youtube.com/watch?v=nkCqgWW5cTQ His "Miss Blues' Child" album is pretty minimalist and what you asked for, though some of his other stuff is a bit more hard rock oriented.

Another vote for Junior Kimbrough, the guy is incredible.

Thirding. His juke joint vids are especially good, metal fucking bass there.

You can never go wrong with the 3 Kings: B.B., Albert, and Freddie. Albert especially.

Muddy Waters <3