The National Football League, as alas many other folks, might think there is a “black national anthem.” But in fact, of course, African Americans share the same national anthem with all other Americans, “The Star-Spangled Banner.” And I bet James Weldon Johnson would have agreed. Who’s he? Among other things, this distinguished American was the coauthor (with his brother) of the song “Lift Every Voice and Sing,” which is often referred to as the black national anthem. But Mr. Johnson referred to it instead as the “Negro National Hymn,” which makes a lot more sense if we’re all Americans.