Terrorism

The United States has had many terrorist attacks, whether directly on US soil, or targeted embassies around the world. The most well know was September 11th, 2001 when terrorists flew planes into the World Trade Center in New York, the Pentagon in DC, and a third plane into a field. These attacks affected the entire US, even those like me who were only in second grade at the time.
Terrorists commit their attacks in order to induce fear into a group of people. The attacks on September 11th definitely fulfilled their mission. People were scared that places with large cities would be targeted in the future, and after learning that an extremist group called al-Queda was behind these attacks, that they'd be back again. I know that it was a much bigger deal for those of us in Boston, a major city, then for people here in Austin or in other places with less national interest. We were pulled out of school for the remainder of the day.
Their motivation is to make us fear them, no matter whether their reasons are religious, political, or personal. Terrorism is meant to affect as many people as possible by one act.
Our country has tried to prevent/deal with terrorist attacks is by increasing the security in airports. This especially increased after 9/11 which was centered around plowing planes into buildings. Security has gotten much more strict, and airline officials limit the amount of liquids and other items that are allowed onto the plane. Also, the CIA and FBI are much more careful and responsive towards potential threats, and intelligence has increased tremendously.
One part of terrorism that is not an intended effect, but often is a large result of an attack, is the fact that people begin thinking that all people like those who were the terrorists, are "evil" and hate Americans. The realization that 9/11 was committed by Muslim extremists, imbued a strong fear of all Muslims, Arabs, and anyone who could appear Muslim. It has taken these eight years to loose that, and even now, as you can see with the current elections and the accusations that Barack Obama is a Muslim, show that Americans have not lost that fear completely.
While 9/11 was by far not the only attack on the United States, it was the most recent and the one that seems to have affected our country the most.