Since the implementation of the General Agreement on Tariffs and Trade (GATT) in 1947, the United States has signed several free trade agreements (FTAs) that have reduced barriers to international trade.  While these agreements traditionally focused on reducing barriers to the free flow of goods, services, and investments, more recent agreements have included provisions that directly affect US immigration law by creating additional nonimmigrant visa classifications to those available under the Immigration and Nationality Act. 
The Immigration and Nationality Act sets forth the nonimmigrant visa classifications by which foreign nationals may enter, work in, or invest in the United States.  Several of the visa classifications, such as the H1-B visa for workers in a specialty occupation and the H2-B visa for seasonal, peak load, or one time need workers, have annual numerical quotas and face chronic and increasingly worse shortages. FTA-created visa classifications, on the other hand, generally do not have the same quotas. Three such visa classifications are the TN visa created by the North American Free Trade Agreement (NAFTA), the E-3 resulting from negotiations during the Australia-United States Free Trade Agreement (AUSFTA), and the H-1B1 created by the US-Chile and US-Singapore Free Trade Agreements. 
The Nonimmigrant NAFTA Professional Visa, or the TN, allows citizens of Mexico and Canada that partake in one of several occupations listed in Schedule 2 of the NAFTA agreement to work in the US for one year with an unlimited possible number of extensions.  Schedule 2 occupations include Management Consultants, Dentists, Attorneys, Medical Technologists and Teachers.  Dependents of TN visa holders may apply for TD status and accompany the principle petitioner to the US.
The E-3 visa applies only to citizens of Australia. Although not formally a part of a free trade agreement but rather a provision in Congress’ Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Tsunami Relief; the creation of the E-3 was negotiated as part of the Australia-United States Free Trade Agreement (AUSFTA) which came into effect in 2005.  The visa is capped at the annual number of 10,500.  The E-3 is similar to the H1-B which allows foreign nationals to come to the United States to perform services in a specialty occupation. It effectively allows Australian professionals who would otherwise be eligible for the H1-B to bypass the quotas plaguing that visa category. Unlike the H1-B, however, the E-3 requires a showing of non-immigrant intent. 
The H-1B1 is part of the US’ free trade agreements with Chile and Singapore. It has the same benefits and requirements as the traditional H-1B but with an additional number of visas available. The FTA established 1,400 visas exclusively for Chilean nationals and 5,400 visas exclusively for Singaporean nationals.  Additionally, H-1B1 beneficiaries may apply at a US consulate abroad without having prior approval from the US Citizenship and Immigration as is required for the traditional H-1B. 
The incorporation of immigration provisions into free trade agreements has its critics. Some argue that they limit Congressional oversight of US immigration policy. Since most are negotiated under a "fast-track" agreement process where an entire agreement must go before Congress for an up and down vote without amendments, Congress has no choice but to go along with the immigration provisions unless it wishes to strike an agreement in its entirety.  Others argue that such provisions shift the focus of free trade talks from reducing barriers on goods, services, and investment, to immigration. Proponents of the provisions argue that Congress still has input into the process since the Senate must ratify all FTAs and Congress may choose not to grant the President fast-track authority. Additionally, immigration is a natural extension of free trade negotiations. Skilled labor is of increasing importance in international commerce and a reduction in barriers on the flow of such labor is vital to promoting global trade. It also gives negotiators an important bargaining chip during trade talks.
The creation of additional nonimmigrant visa categories through FTAs has created new opportunities for US businesses and foreign nationals. As the US continues to partake in free trade negotiations with countries throughout the world, the impact of FTAs on US immigration law will likely continue.
 Duke Law Library, http://www.law.duke.edu/lib/researchguides/gatt.html (Last visited Feb 9, 2008).
 Barbara Wong Loughlin, The US-Singapore/Chile Free Trade Agreements and Their Impact on US Immigration, in IMMIGRATION PRACTICE UNDER NAFTA AND OTHER FREE TRADE AGREEMENTS 35 (Janet H. Cheetham ed., 2007).
 US Citizenship and Immigration Service, http://www.uscis.gov/portal/site/uscis/menuitem.eb1d4c2a3e5b9ac89243c6a7543f6d1a/?vgnextoid=f3829c7755cb9010VgnVCM10000045f3d6a1RCRD&vgnextchannel=f3829c7755cb9010VgnVCM10000045f3d6a1RCRD (last visited Feb 9, 2008).
 Supra note 2 at 36.
 US Department of State, http://travel.state.gov/visa/temp/types/types_1274.html (last visited Feb. 9, 2008).
 Supra note 2 at 40; Australia Free Trade Agreements, http://www.fta.gov.au/default.aspx?FolderID=246&ArticleID=193 (last visited Feb. 9, 2008).
 Supra note 2 at 40.
 Supra note 2 at 40.
 Supra note 2 at 38.
 Supra note 2 at 40.
 Supra note 2 at 42.