Over the past 10 years the fastest white South African1 sprinters.
2017 - Emile Erasmus 10.08
2016 - Emile Erasmus 10.21
2015 - Danie Van Blerk 10.23 (-2.0 wind)
2014 -Emile Erasmus 10.23
2013 - Hannes Dreyer 10.21
2012 - Hannes Dreyer 10.23
2011 - Hannes Dreyer 10.27
2010 - No one under 10.30
2009 - No one under 10.30
2008 - Hannes Dreyer 10.24
Now compare that to the fastest white US sprinters over the past 10 years.
2017 - Blake Smith 10.28, possibly Wayne Sherbahn 10.22 (not sure if wind recorded)
2016 - John Teeters 10.00
2015 - John Teeters 10.07
2014 - John Teeters 10.14
2013 - John Teeters 10.27
2012 - couldn't find anyone under 10.30
2011 - Shane Crawford 10.18
2010 - couldn't find anyone under 10.30
2009 - couldn't find anyone under 10.30
2008 - couldn't find anyone under 10.30
The last 10 years has seen South Africa produce a faster white sprinter than the US 4 times. The US has produced a faster white sprinter 4 times as well. 2 years(2009/2010) were a wash with neither country producing a white sprinter under 10.30. This data is pretty telling. South Africa has a white population of 5 million. The US has a white population of about 230 million. It's absurd that South Africa has been able to basically match the US in white sprinting with 1/46th the population. What this data really tells me is that white kids in America don't really care about sprinting. If they did, it would stand to reason there would be a lot more whites running top times out of the US.
DISCLAIMER - IF MY LISTS ARE INACCURATE, FEEL FREE TO CORRECT THEM! I did my best to find the fastest white sprinters for the US which proved challenging because I couldn't find many pictures from the earlier years on the list.