In the Blood by Charles Barber

 This is the story of 2 men in Connecticut who were determined to improve the lot of injured soldiers fighting overseas. Frank Hursey devised a product that would stop bleeding in cases of severe injury. He didn't have much success with the product until he hired Burt Gullong, who became a super salesman. The two had to start from scratch learning about FDA approvals and how to get products on the military formulary. They also came up against one very stubborn Army doctor who was determined not to recommend their product as he backed not one but two other clotting products--one of which didn't work and the other of which had dangerous side effects. It really is an inspiring story of perseverence because they were certain that this product (and its later iterations) really could save lives.