So, the good news is that this is a wonderful clear autograph of William Wilberforce neatly situated in the remains of a letter that was entirely in his hand. The bad news is that at some point, someone separated this from the remainder of the letter, which would have been of great historical significance.

The letter was written to his brother-in-law, James Stephen. He was a lawyer and is today considered the chief legal mind behind the rather ingenious crafting of the 1807 Anti-Slavery Bill. His final speaking engagement was at the Anti-Slavery Convention of 1832. 

What remains of the text is a reference to hoping Wilberforce's sister is feeling better [Stephen's wife], a reference to the Christian Guardian, a partial address panel, and a few remains of text on the rear. 

Intact, this would have been a $1200-$1500 letter. Still, a very nice framing example with an original wonderful "situ."