September 11 attacks
The September 11 attacks (also referred to as 9/11) were a series of four coordinated terrorist attacks by the Islamic terrorist group al-Qaeda against the United States on the morning of Tuesday, September 11, 2001. The attacks killed 2,996 people, injured over 6,000 others, and caused at least $10 billion in infrastructure and property damage. Additional people died of 9/11-related cancer and respiratory diseases in the months and years following the attacks.
History of laws concerning immigration and naturalization in the United States
The terrorist attacks on September 11, 2001 affected American perspectives on many issues, including immigration. A total of 20 foreign terrorists were involved, 19 of whom took part in the attacks that caused the deaths of 2,977 victims, most of them civilians. The terrorists had entered the United States on tourist or student visas. Four of them, however, had violated the terms of their visas. The attack exposed long-standing weaknesses in the U.S. immigration system that included failures in the areas of visa processing, internal enforcement, and information sharing.