At the Athens Olympics in 2004, Hennagan was part of the United States team which finished first in the 4×400 meters relay.
This result has been in doubt since 2010 after Crystal Cox, who ran for the team in a preliminary round, admitted to using doping. Cox"s drug violation puts the entire teams gold medal in jeopardy, however as of 2012 the American team ( apart from Cox ) retain their gold medals. In 2008, Hennagan had her relay medal from the 4 X 400 metre relay from 2000 Olympics stripped because of teammate Marion Jones admitting to performance enhancing drug use.
100 metres: 11.26 seconds (2005)
200 metres: 22.87 seconds (2005)
400 metres: 49.56 seconds (2004).