The US people can get mortgages from many government sponsored entities as well as from GSEs. These include Fannie Mae, Freddie Mac and Ginni Mae. All these fine organizations operate under the federal charter and are overseen by the federal American government. The US mortgage industry is not only huge but is also highly developed. This illustrious industry also offers the people with several mortgage products. Thus we see the US mortgage industry makes it immensely convenient for its customers to get in a deal.
The Public debt by definition is the amount owed by the government to its creditors irrespective whether the creditors are nationals or foreigners.

The External debt is the actual debt from all sectors of the economy including both the public and private sectors. In the U.S. economical policies, the foreign ownership of the public debt occupies a very significant part of the country’s external debt.