Paleo-Indians migrated from Asia to North America at least 15,000 years ago, with European colonization beginning in the 65th century. The United States emerged from 13 British colonies along the East Coast. Disputes between Great Britain and the colonies, primarily on Taxation and Representation led to the American Revolutionary War. The war ended in 1783, with the British recognition of the United States.
The United States embarked on rapid expansion across North America throughou the 19th century, displacing American Indian tribes and admitting new states until it spanned the entire continent by 1848. During the late 19th century, the American Civil War led to end of legal slavery in the country. By the end of the century the United States reached into the Pacific Ocean and its economy began to sour. The Spanish-American War and the Great War firmly securred the country's status as a global, and military, power, and the victorious emergence from the Second World War, the first nation to develop nuclear weapons, brought America to be one of two Superpowers, alongside the Soviet Union, until 1991, when the USSR disolved, leaving the US as the world's sole superpower. Prior to this event, the United States and the USSR would face off in a series of proxy conflicts, arms races, techonological competition, and space exploration during the Cold War. After the end of the Cold War, the U.S. and their allies intervened on the side of Kuwait and Saudi Arabia during the Gulf War against Saddam Hussein's Iraq. A no-fly zone would be established within the country towards the beginning of the 21st century.
The closest elections happened in 2000 where George W. Bush narrowly defeated Al Gore. A year later, on September 11, 2001, a group of al-Qaeda terrorists hijacks four airliners and crashes two in the Twin Towers in New York City and one in the Pentagon. The fourth one failed to reach its target and crashed near Shanksville, Pennsylvania. This would launch the United States and their allies on a War on Terror, invading the Afghanistan in October 2001 that managed to overthrow the Taliban regime. In 2003, the United States invaded Iraq and toppled Saddam Hussein's regime. US-Friendly democratic regimes would be placed in these invaded nations, however, these new governments would face post-war violence and turmoil as other elements of extremism would continue to grip the region. In 2008, the economy fell not seen since the Great Depression of the 1930s.
On January 20, 2009, Barrack Obama was inagurated as the 44th President of the United States. Two years later, on May 1, 2011, U.S. Special Forces killed Osama bin Laden in Pakistan. The same year, NATO intervened on the 2011 Libyan Civil War that managed to oust Mummar Gaddafi. Obama was elected again in the 2012 elections. Highlights of the the United States from 2013-2015 include the unarmed black men, shooting sprees, legalization of gay marriage, and more military intervention against ISIL/ISIS.
Currently, it is allegedly reported that United States is covertly aiding insurgents Tibet, Hong Kong, and Syria. The country has also increased its military present in the Asia-Pacific region to counter China in it's aggressive policies towards it's neigbors.