can someone explain american history from the first inhabitants over 12000 years ago through 1865?

~The "indigenous" 'natives' migrated into the Americas and proceeded to kill each other off until the Europeans arrived and started killing all them off. Once that job was well in hand, the European migrants started to kill each other off. For kicks, they imported Africans to do the work for them so they had more time to kill each other and the 'natives'. Of course, they needed railroads and laundries (not to mention opium and restaurants), so the Europeans imported Asians, too.

Good heavens! ...... Ancestors of the people we call 'Native Americans' migrated into the area of today's US after the Ice Age, supposedly by crossing the Bering Strait from Asia. Typically they lived in villages or pueblos that were substantially self-sufficient, though also trading with each other. In each village they were weaving baskets, wearing jewelry, sustaining nature-based religious practises, and eating corn and vegetables that they grew, fish from rivers lakes or the sea, and meat they obtained by hunting or trapping. In the 1500s, the Spanish colonised Mexico and over the next 300 years they explored from there into Florida and other areas now in the southern half of the US. Other Europeans arrived from France, Britain, Netherlands, etc and founded colonies on the east and Gulf coasts such as Plymouth (MA, British), Mobile (AL) and New Orleans (French), and New Amsterdam (Dutch; now New York). A war in 1756-63 ended with the British in control of 13 colonies covering almost the whole east coast. These colonies declared independence in 1776 as a union, the United States. They won their war of independence (1781). The United States then expanded westward, taking over the rest of the present USA either by purchase (in particular, most of the Plains from France in 1803) by war (e.g. most of the Southwest and California form Mexico in 1846) or by agreement (e.g. Texas).