The United States, as we understand it, has existed as a political entity since the ratification of the American Constitution in 1789.However, this can be debated, as some historians use dates such as the founding of America in or 1775, the start of the American War of Independence, or the declaration of independence by the 13 counties in 1776.The United States is the most powerful nation on our planet and lives in the best territory on earth.The United States has the best neighbours and lives in the best neighbourhood of any country worldwide.Furthermore, the United States is blessed to have been created in the late 18th century at the dawn of the , which started in 1769 in Great Britain.What this meant for the United States was that it managed to grow and continue to grow in times of phenomenal technological change, which meant that a political entity could hold itself together because technologies like the railways, Telegraph and phones managed to maintain that massive political entity together.If you want to compare China with the United States, it was a unified political entity in .