USPS (United States Postal Service) is an official provider of postal services in the United States of America. This company was established more than 200 years ago and still remains the biggest mail delivery service in the country. USPS also serves American Army postal addresses outside of the US. It is a truly giant organization that operates a gigantic fleet of vehicle freight carriers. With over 750,000 employees it ranks third among America’s largest employers trailing only to United States Department of Defense and retail chain Wall-Mart.