I just finished the ebook version of John Pipes'

Amazing Grace in the Life of William Wilberforce (80 pgs. PDF, but there are a lot of blank pages, so it will print up correctly. I just downloaded it and read it off my computer, so I found the blanks mildly annoying.)

It was quite good. This is from the penultimate paragraph:

The joy of the Lord became his strength (Neh. 8:10). And in this strength he pressed on in the cause of abolishing the slave trade until he had the victory.

The rest of the book provides the proof of that statement.