Two employees from PayPal started YouTube which has become a major social media
Hurricane Katrina was a major catastrophe killing approximately 1,800 people and causing more than $81 billion in damages.
Seung-Hui Cho killed 32 people and wounded many others before killing himself at Virginia Tech University in Blackburg, Va. The massacre is the deadliest peacetime shooting incident by a single gunman in U.S. history.
The United States (and much of the world) entered a major recession that saw home foreclosures, bank failures and job losses.
The price of petroleum hits $100 per barrel for the first time in history
April -The Deepwater Horizon oil platform explodes in the Gulf of Mexico, killing eleven workers. In the months that follow, an estimated 205.8 million gallons of crude oil spill into the water, damaging an estimated area of 80,000 square kilometers
Over 90,000 internal reports about the United States-led involvement in the War in Afghanistan from 2004 to 2010 are leaked to the public via Wikileaks, an online publisher of anonymous, covert, and classified material.
Osama bin Laden was the head of al-Qaeda, the terrorist group responsible for the terrorist attacks of September 11, 2011. On May 2, 2011, U.S. forces invaded his compound in Pakistan. Bin Laden was killed in the raid.
A protest at a New York City park near Wall Street, airing complaints that the richest 1 percent of Americans benefit at the expense of the rest, spread to scores of communities across the U.S. and abroad.
Hurricane Sandy causes at least 132 deaths and an estimated 82 billion in damages, making it the second costliest hurricane in the U.S., behind Katrina. New Jersey, New York, and Connecticut are hardest hit
It is revealed that the National Security Agency (NSA) is spying on the web activities, including email, of U.S. citizens.
The Affordable Care Act, Obamacare, begins registering people for the expanded federal government health insurance.