There are plenty of books on the work of Billy Graham, but not nearly as many on Harold John Ockenga, the man behind much of what Billy Graham and his ministry achieved by God's grace. I had not heard of Ockenga before my church history course but after reading the book I have to wonder how that was the case. Ockenga was God's man behind the 4th Great Awakening and the Rebirth of Evangelicalism. This book goes into incredible detail of his life and ministry.
Garth Rosell was asked by Ockenga's family to write this biography (as his father, Carl Rosell, was another key member of the Awakening movement) and granted him permissions to all of Ockenga's journals and private works to do so. He gives great back story to the great Awakening and captured well the impact of Ockenga and Graham's work. Ockenga was an enormously powerful preacher and evangelist(though quite awkward with the ladies as you'd find in this book). He was part of the first graduating class of Westminster Seminary, founded by J. Gresham Machem after the split within the Presbyterians from Princeton and eventually the founder and president of the ever-important National Association of Evangelicals and Fuller Seminary.
I think what may have impressed me the most is the humility and accountability that these men had in the midst of their incredible success in ministry. They would do speaking engagements and conferences together and draw huge crowds, but as Rosell states, "while any fair-minded observer would judge people like Billy Graham, Percy Crawford, Merv Rosell, Hyman Appleman, and Jack Wyrtzen to be genuinely remarkable individuals, the evangelists themselves were without exception convinced that anything of value they accomplished was because of God's power rather than any human abilities they might possess." These men were genuinely humble and seeking the Glory of God alone.
In short, I think you could make the assessment that Harold John Ockenga and Billy Graham were to the Fourth Great Awakening what Jonathan Edwards and George Whitefield were to the First Great Awakening. Rosell does a fine job of showing how these incredible men were used immensely by our incomparable God.