Britain's American colonies broke with the mother country in 1776 and were recognized as the new nation of the United States of America following the Treaty of Paris in 1783. During the 19th and 20th centuries, 37 new states were added to the original 13 as the nation expanded across the North American continent and acquired a number of overseas possessions. The two most traumatic experiences in the nation's history were the Civil War (1861-65) and the Great Depression of the 1930s. Buoyed by victories in World Wars I and II and the end of the Cold War in 1991, the US remains the world's most powerful nation-state. The economy is marked by steady growth, low unemployment and inflation, and rapid advances in technology.The USA is a huge country to explore, with 50 states to choose from, flanked by two oceans and covering an incredibly varied terrain. For five centuries, since the ‘New World’ discoveries of Christopher Columbus, people from every corner of the globe have come here in search of ‘the American Dream’. Between them, they have created the richest, most powerful country on earth, and a fascinating melting pot of cultures and traditions. Tourism centres mainly on the subtropical states of Florida, California and Hawaii, the winter ski resorts and the huge metropolises. But it is the astonishing, vast landscapes that make the USA truly distinctive – spectacular National Parks like Yosemite and the Everglades, rugged ice fields, the Great Lakes and the desert plains – and such awe-inspiring sights as the Grand Canyon and the Rocky Mountains should be on every visitor’s must-see list. As Gertrude Stein remarked: “In the United States there is more space where nobody is than where anybody is. That is what makes America what it is.”