The US shot for six relay titles in a row - and boy did they get it.
The US Women had a phenominal night last night too. They smashed the 4x100m relay record with a time of 40.82, more than a half-second better than a record that had stood for 27 years.
Today's 4x400m record left Team US with the fourth fastest 4x400m relay time in history, with a final time of 3:16.88. These girls were dominant from start to finish, with Russia and Jamaica finishing in second and third.