Here is what wikipedia.org has to say:
John Hugh Niland (born February 29, 1944 in Quincy, Massachusetts) is a former American football offensive lineman in the National Football League from 1966 through 1975. He played college football at the University of Iowa where he was an All-American selection in (1965). He was also a Second-team All-America selection in 1964 by the Newspaper Enterprise Association. Additionally, he was drafted in the first round (fifth overal) of the 1966 NFL Draft by the Dallas Cowboys.
He played guard for the Cowboys for nine seasons. One of the top offensive lineman of his era, and an excellent pulling guard, Niland was selected to six consecutive Pro Bowls and was an All-Pro. Niland was traded to the Philadelphia Eagles in 1975. He played one season for the Eagles before retiring.
10 Ron Widby | 12 Roger Staubach (MVP) | 14 Craig Morton | 15 Toni Fritsch | 19 Lance Alworth | 20 Mel Renfro | 22 Bob Hayes | 23 Margene Adkins | 26 Herb Adderley | 30 Dan Reeves | 31 Gloster Richardson | 32 Walt Garrison | 33 Duane Thomas | 34 Cornell Green | 35 Calvin Hill | 36 Joe Williams | 37 Isaac Thomas | 41 Charlie Waters | 42 Claxton Welch | 43 Cliff Harris | 46 Mark Washington | 50 D. D. Lewis | 51 Dave Manders | 52 Dave Edwards | 54 Chuck Howley | 55 Lee Roy Jordan | 56 Tom Stincic | 60 Lee Roy Caffey | 61 Blaine Nye | 62 John Fitzgerald | 63 Larry Cole | 64 Tony Liscio | 66 George Andrie | 67 Pat Toomay | 70 Rayfield Wright | 71 Rodney Wallace | 72 Don Talbert | 73 Ralph Neely | 74 Bob Lilly | 75 Jethro Pugh | 76 John Niland | 77 Bill Gregory | 79 Forrest Gregg | 83 Mike Clark | 85 Tody Smith | 87 Billy Truax | 89 Mike Ditka
Head Coach: Tom Landry
Coaches: Ermal Allen | Bobby Franklin | Jim Myers | Dan Reeves | Ray Renfro | Ernie Stautner | Jerry Tubbs