The mid-60's Cardinals wouldn't have had a play called "n****** go deep." Their receivers, Wide outs Sonny Randle and Bobby Jo Conrad, and TE Jackie Smith, were white. I recall the expression though. It was in Dan Jenkins' 1972 novel, "Semi-Tough." Oddly, the protagonist of the novel, Billy Clyde Puckett, was a white running back with Jim Brown's physical talent. The character was from Jenkins' high school and college, Paschal High in Fort Worth and TCU. The reviewers of the time were either too stupid or didn't want to admit it, but there was a 60's white RB who fit the description, Joe Don Looney, who went to Paschal High. In a 1971 book, Fran Tarkenton said: "Joe Don Looney blew out of Oklahoma with the credentials to be another Jimmy Brown." Unfortunately, Looney was the Johnny Manziel of his day.