Just wanted to pass on a good book for those that have an interest in WW2 fighters, the P-51 in particular. The book is "P-51 Mustang: Development of the long-range escort fighter" by Paul Ludwig. It covers the history of the development of the Mustang and describes all the politics and biases that those in charge of not only development and procurement of fighters, but placing the Mustang into operational service as an escort and not just a fighter-bomber.
I knew the basics of the story behind the P-51, but this book really goes into detail about how close it came to not becoming arguably the greatest escort fighter of all time.