USDA declares 2012 drought largest natural disaster in U.S. history

NATIONAL -- The lack of rain and scorching heat is impacting half the country.

With half the country in a massive drought, the USDA has declared the drought of 2012 the largest natural disaster in U.S. history.

And corn farmers say that without more rain, their crops will be ruined.

The dry spell followed a blistering heat wave where more than 170 all-time temperature records were broken or tied.