United States of America is the world’s most ethnically diverse and multicultural nation, the product of large-scale immigration from many countries. USA is a highly developed country having the world’s largest national economy in terms of real GDP, having gift of plenty of natural resources and the worker productivity is immensely high. USA is famous for its R&D and is known to be the world’s biggest military power, having a known political and cultural persona, and is a reputed a leader in scientific research and technological innovations.
A citizen of the United States is an “American”. “United States”, “American” and “U.S.” refer to the country adjectivally.
The United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations