No, the United States of America did not default on its debts in 2013. As the year is almost over, even if another government shutdown crisis occurred, the likelihood that the US would default on its debts is nigh impossible. Whether or not the US defaults on its debts in 2014 remains to be seen.
America is the biggest economy in the world, with some of the leading industries and services in the world. This tremendous wealth represents an opportunity to investors around the world. America has never defaulted on it's debt in it's nearly 240 year history and has had bigger debts in the past which it has paid off.