INTRODUCTION TO HISTORY:
The Declaration of Independence, announcing the separation of the colonies from Great Britain, and establishing themselves at the United States, is considered the most important of all American documents, and a national symbol of liberty. Thomas Jefferson drafted the document between June 11 - June 28, 1776. His unparalleled exUS IMMIGRATION HISTORY

The following information is not meant to be a definitive account of the history of US immigration. Its objective is to give viewers an insight and cursory glimpse into the "making of present day America".

The First Americans
It has long been a spirited topic of debate as to who got here first. The mosaic palate of peoples and cultures which represents today's America heightens the intensity of such a debate. Discoveries made by various anthropologists of human remains over the past few decades provide evidence that long before Ellis Island opened its doors to welcome those seeking political and religious freedom as well as the "adventurer, the wanderer, the persecuted, the fortune seekers, and others" America was a kaleidoscope of ethnic and cultural groups! Thus, the history of US immigration spans a long period of migration of many different peoples from various parts of the world. One common belief is that America was originally peopled by wanderers from Northeast Asia about 20,000 years ago. These wanderers were believed by some to be the founding population (and ancestors!) of today's Native Americans. Others believe that the first Americans came from Polynesia, South Asia or even Europe. Even others believe that the very first Americans were killed by later arrivals and that they left no descendants. The debate rages on! However, not to be lost in this debate is the fact that whether 20,000, 10,000 or 1,000 years ago, most immigrant groups to America came full of hopes and dreams of the "Promised Land". Around the year 1000, a small number of Vikings arrived. Five hundred years later, the great European migration began. In some cases, the co-existence of Europeans and Native Americans was peaceful. In other cases, there were cultural clashes, leading to violence and disease. Many settlers from Europe and Asia came to seek their fortune in a new country which was thought to have unlimited resources. Many people from Africa, however, were bought here against their will to work as forced laborers in the building of a new nation. As early as 1619, slaves from Africa and the Caribbean were brought forcibly to America. The information appearing below will cover only the past 400 years of US immigration.
The Declaration of Independence
pression of "self-evident truths" conveyed the convictions of the American people for individual liberty and enumerated their grievances against the King to justify their breaking from the mother country.
Read the Declaration of Independence
Read the Constitution of the United States
The Declaration of Independence asserts the fundamental American ideal of government, but it was based upon the theory of "natural rights" previously proclaimed by writers : John Locke, Emerich Vattel and Jean Jacques Rousseau. The Declaration was adopted on July 4, 1776.
European Migration
The settling of America began with an idea. The idea was that people can join together and agree to govern themselves by making laws for the common good. With that idea in mind, 102 English colonists (later referred to as the "Pilgrims") set sail in 1620 on the Mayflower. They landed in Plymouth, Massachusetts. This is generally considered by many to be the "start" of planned European migration! In 1638, just 18 years after the Mayflower, the Swedes began their migration to America. Unlike the Pilgrim Fathers, the Swedes were not religious dissenters - they were an organized group of colonizers sent by the Swedish Government to establish a colony in Delaware. In 1655, the colony was lost to the Dutch. In the mid-1840s, a wave of Swedish migration began with the landing of a group of migrant farmers in New York and continued up to World War I. During the colonial era most of the immigrants to the U.S. came from Northern Europe. Their numbers declined during the 1770s, but picked up during the mid 1800s. New arrivals came from several countries, but mostly from Germany and Ireland where crop failures caused many to leave their homelands. Other groups also arrived from the Netherlands, Spain, Italy, the Scandinavian countries, and Eastern Europe.
US immigration Today
It has long been a spirited topic of debate as to who got here first. The mosaic palate of peoples and cultures which represents today's America heightens the intensity of such a debate. Discoveries made by various anthropologists of human remains over the past few decades provide evidence that long before Ellis Island opened its doors to welcome those seeking political and religious freedom as well as the "adventurer, the wanderer, the persecuted, the fortune seekers, and others" America was a kaleidoscope of ethnic and cultural groups! Thus, the history of US immigration spans a long period of migration of many different peoples from various parts of the world. One common belief is that America was originally peopled by wanderers from Northeast Asia about 20,000 years ago. These wanderers were believed by some to be the founding population (and ancestors!) of today's Native Americans. Others believe that the first Americans came from Polynesia, South Asia or even Europe.
Even others believe that the very first Americans were killed by later arrivals and that they left no descendants.
The debate rages on! However, not to be lost in this debate is the fact that whether 20,000, 10,000 or 1,000 years ago, most immigrant groups to America came full of hopes and dreams of the "Promised Land". Around the year 1000, a small number of Vikings arrived. Five hundred years later, the great European migration began. In some cases, the co-existence of Europeans and Native Americans was peaceful. In other cases, there were cultural clashes, leading to violence and disease.
Many settlers from Europe and Asia came to seek their fortune in a new country which was thought to have unlimited resources. Many people from Africa, however, were bought here against their will to work as forced laborers in the building of a new nation. As early as 1619, slaves from Africa and the Caribbean were brought forcibly to America. The information appearing below will cover only the past 400 years of US immigration.
Significant Historic Dates in U.S. Immigration
Naturalization Act of 1790: Stipulated that "any alien, being a free white person, may be admitted to become a citizen of the United States"
1875: Supreme Court declared that regulation of US immigration is the responsibility of the Federal Government.
1882 The Chinese Exclusion Act: Prohibited certain laborers from immigrating to the United States.
1885 and 1887: Alien Contract Labor laws which prohibited certain laborers from immigrating to the United States.
1891: The Federal Government assumed the task of inspecting, admitting, rejecting, and processing all immigrants seeking admission to the U.S.
1892: On January 2, a new Federal US immigration station opened on Ellis Island in New York Harbor.
1903: This Act restated the 1891 provisions concerning land borders and called for rules covering entry as well as inspection of aliens crossing the Mexican border.
1907 The US immigration Act of 1907: Reorganized the states bordering Mexico (Arizona, New Mexico and a large part of Texas) into Mexican Border District to stem the flow of immigrants into the United States.
1917 - 1924: A series of laws were enacted to further limit the number of new immigrants. These laws established the quota system and imposed passport requirements. They expanded the categories of excludable aliens and banned all Asians except Japanese.
1924 Act: Reduced the number of US immigration visas and allocated them on the basis of national origin.
1940 The Alien Registration Act: Required all aliens (non-U.S. citizens) within the United States to register with the Government and receive an Alien Registration Receipt Card (the predecessor of the "Green Card").
1950 Passage of the Internal Security Act: Rendered the Alien Registration Receipt Card even more valuable. Immigrants with legal status had their cards replaced with what generally became known as the "green card" (Form I-151).
1952 Act: Established the modern day US immigration system. It created a quota system which imposes limits on a per-country basis. It also established the preference system that gave priority to family members and people with special skills.
1968 Act: Eliminated US immigration discrimination based on race, place of birth, sex and residence. It also officially abolished restrictions on Oriental US immigration.
1976 Act: Eliminated preferential treatment for residents of the Western Hemisphere.
1980 Act: Established a general policy governing the admission of refugees.
1986 Act: Focused on curtailing illegal US immigration. It legalized hundred of thousands of illegal immigrants. The 1986 Immigration Act is commonly know as the 1986 Immigration Amnesty. It also introduced the employer sanctions program which fines employers for hiring illegal workers. It also passed tough laws to prevent bogus marriage fraud.
1990 Act: Established an annual limit for certain categories of immigrants. It was aimed at helping U.S. businesses attract skilled foreign workers; thus, it expanded the business class categories to favor persons who can make educational, professional or financial contributions. It created the Immigrant Investor Program.
USA Patriot Act 2001: Uniting and Strengthening America by providing appropriate tools required to intercept and obstruct terrorism.
Creation of the USCIS 2003: As of March 1, 2003, the US immigration and Naturalization Service (INS) becomes part of the Department of Homeland Security (DHS). The department’s new U.S. Citizenship and US immigration Services (USCIS) function is to handle US immigration services and benefits, including citizenship, applications for permanent residence, non-immigrant applications, asylum, and refugee services. US immigration enforcement functions are now under the Department's Border and Transportation Security Directorate, known as the Bureau of US immigration and Customs Enforcement (ICE).

Information:
Current Army regulations prohibit granting a Security Clearance to non-U.S. citizens. Additionally, some Army jobs may only be performed by U.S. citizens, regardless of Security Clearance requirements.
Below are Army jobs that can be performed by Non-U.S. Citizens:
http://usmilitary.about.com/od/enlistedjobs/a/noncitizen.-uMT.htm