How long has the United States been founded?

The United States was the first place where Indians lived. At the end of 15, Spain, the Netherlands, France and Britain immigrated here one after another. 13 Before the 8th century, Britain established13 British North American colony on the Atlantic coast of the United States. 1775, the American people broke out the war of independence against the colonial rule of the British Empire. 1776 On July 4th, the Second Continental Congress was held in Philadelphia. George Washington was the commander-in-chief of the Continental Army and issued the Declaration of Independence, announcing the formal establishment of the United States of America.

natural resource

The United States is rich in natural resources, and the total proven reserves of mineral resources rank first in the world. Coal, oil, natural gas, iron ore, potassium salt, phosphate, sulfur and other mineral reserves rank among the top in the world. Other minerals mainly include copper, lead, molybdenum, uranium, bauxite, gold, mercury, nickel, potassium carbonate, silver, tungsten, zinc, aluminum and bismuth. Strategic mineral resources such as titanium, manganese, cobalt and chromium mainly rely on imports. The forest area is about 4.4 billion mu, with a coverage rate of 33%.