Join author James Lilliefors on his journey through Ball Cap Nation. As the country grows increasingly diverse and complicated, Americans seek, and occasionally find, a common thread to unite them. And, as Jim Lilliefors reveals in his new book, that common thread is what the baseball cap is made of -- indeed, what has transformed it into America's National Hat. As fads go, it's no longer even a fad, but a part of the national...