In looking at the history of this thread and after reading Don's comment on white purge about Czonka and Riggins being some of the last feature RB's, 100 yard games, 1,000 yard seasons, etc. It made me think about the 1970's Oakland Raiders who had 3 white RB's on their 1975 roster who all played significantly and or were the feature back. Amazingly, it's a reminder of how things suddenly changed!
Marv Hubbard was Oakland's feature RB in the early 70's who had a 1,000- yard season, (1,100, 5.0 ypa), 1972. Averaged 4.8 yards/carry for his career!
Pete Banaszak, out of Miami no less, was a feature back for Oakland in the late 60's. He led the league in rushing TD's, (16) in 1975.
Mark van Eeghen, probably the best of the 3 and possibly the second or third best white RB of the 70's, behind Czonka. Riggins. He had 3 consecutive 1,000 yard seasons. 1976, 1977, and 1978. Won 2 super bowls.
Again, all three of these great white RB's on the same Oakland Raider roster in 1975!