Following the terrorist attacks of September 11, 2001, the United States has implemented many changes in regards to national security. Many of those changes effect immigration to the United States. More specifically, obtaining a visa for travel and immigration to the United States has become increasingly difficult following the events of September 11. Previously, before 9/11, applicants were only required to fill out one application. Now, however, the USCIS (formerly known as the Immigration and Naturalization Service) may require up to 3 or more forms and many visas undergo much scrutiny. To deal with the greater number of applicants and the forms they are submitting, funding was increased to hire additional USCIS personnel. However, the backlog of cases still persists. Some of the additional forms required by the United States ask questions such as if the applicant has previously stayed in a Middle Eastern country or has traveled close by. Other questions may include if the applicant has knowledge on explosives and rifles. The extra checks and interrogations are conducted with the intention of preventing terrorists from entering the United States. Before September 11, the immigration officer would stamp passports for a visits up to 6 months. Currently, USCIS regulations are different and before the passport is stamped by the immigration officer, travelers usually face long interrogations pertaining to their length and location of stay. In addition, the stamp is no longer valid for 6 months but usually only 30 days. If the visit is longer than the 30 days, the immigration office must be informed. Not reporting a change of address may result in problems for the individual on the visa. An extension to stay in the U.S. longer than 30 days may be granted in some cases. In 2005 the U.S. Department of State claimed that slightly more than 2% of their visa applicants underwent additional scrutiny.

Some of the individuals that are being affected by the delays in visa processing are students. Since 9/11 American schools throughout the country have seen a drop in the number of foreign students applying. Some university officials claim that a contributing factor in the drop of foreign applicants is that European and Australian universities are attracting more foreign students. Obtaining a visa to study in a country besides the United States may be of less difficulty. Another claim is that visa process is taking longer than before in the US due to the additional requirements introduced after September 11 coupled with additional visa scrutiny.

Some of the top reasons why visas are denied or delayed include:  (1) Difficulty proving that the applicant is not intending to immigrate to the US, (2) Security clearances that are sometimes required, and (3) The interview done by a consular officer that is required for most non-immigrant visa applicants. The U.S. Department of State has been working on improvements such as hiring more personnel at their embassies and consulates, reducing average processing times, and giving priority to exchange visitors and students.

In addition to visa applicants sometimes having to face delays, some face additional scrutiny airports and other port of entries. Most likely, if an applicant is from a country with strong terrorist ties or their name is similar to a name on a "terrorist watch list," they are more likely to be interrogated. In addition, males with an Arab or Muslim background aged from 16 to 45 years old may be fingerprinted and photographed at airports and other border crossings. The U.S. Department of State has assembled a list of countries with possible terrorism ties. Government officials insist that this is by no means ethnic profiling and that criteria is based upon intelligence reports. Racial and ethnic profiling has been banned throughout federal agencies. There are instances when authorities receive specific information about a certain ethnic or racial groups that may be suspected of orchestrating a terrorist attack. In these instances, federal guidelines allow immigration officers to further scrutinize certain ethnicities. However, there have been numerous complaints that certain groups are singled out at airports due to the stereotypes that exist. Regardless, one concrete result of the terrorist attacks of September 11 are that all individuals, both U.S. citizens or non-citizens, have to undergo increased security measures when traveling in the United States.