I just finished the Wright Brothers, which I enjoyed, even though I don't think it's one of McCullough's best books. My main criticisms? The treatment of the events of December 1903 get relatively short shrift, especially compared to the elongated discussions of the Wright Brothers' adventures in France. Mainly, however, he provides almost no information about the patent lawsuits that preoccupied Wilbur until he died. I learned more about them from Wikipedia. Still, it's a good and fast read.