A more thorough explanation:

The United States of America is a federal republic that was formed after the War of Independence. It is made up of 48 conterminous states, which means they share a common boundary, plus the state of Alaska and the District of Columbia in North America, and the state of Hawaii in the Pacific. The abbreviation for the United States of America is USA.

• The capital of the United States of America is Washington D.C.
• The United States of America is the third largest country in the world by land area.
• The United States of America has a population of over 328 million people.

These examples illustrate the definition of the United States of America by providing additional information about the country. The first example shows that the District of Columbia is the capital of the country. The second example provides information about the size of the country. The third example gives an idea of the population of the United States of America.