Got my green card, finally! My colleague sent me information about the history of green card.
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Post World War II—The First Green Card
As World War II ended and large-scale immigration to the United States resumed, alien registration ceased to take place at post offices and became part of regular immigration procedures at ports of entry. INS, based on the alien's admission status, issued different documents to serve as Alien Registration Receipt Cards. For example, visitors received an I-94c, temporary foreign laborers received an I-100a, and legal permanent residents (LPRs) received an I-151. The small, green Form I-151 had immediate value in identifying its holder as an alien who was entitled to live and work indefinitely in the United States.
Combating Document Fraud—The Green Card Changes Color
In the early 1950s, the status of being a Green Card holder became so desirable that counterfeit Form I-151s became a serious problem. To combat document fraud, the INS issued 17 different re-designs of the Form I-151 between 1952 and its complete revision in 1977.
In 1964, the color of the Green Card was changed to pale blue. After 1964, it became a dark blue. Regardless of color, the Form I-151 still carried with it the benefits indicated by the term Green Card, and those who wanted, obtained, issued or inspected it continued to refer to it by that name.
During the mid-1970s, INS studied methods to produce a more counterfeit-resistant Green Card. The study resulted in centralized card production at the Immigration Card Facility in Texas. This created standardization and accountability lacking with local card production. In addition, new materials and technologies were introduced to create a new machine-verifiable Green Card. The new Green Card, first issued in 1977, also had a new form number, I-551.
http://www.usa.or.th/news/press/1998/nrot079t.htm
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Post World War II—The First Green Card
As World War II ended and large-scale immigration to the United States resumed, alien registration ceased to take place at post offices and became part of regular immigration procedures at ports of entry. INS, based on the alien's admission status, issued different documents to serve as Alien Registration Receipt Cards. For example, visitors received an I-94c, temporary foreign laborers received an I-100a, and legal permanent residents (LPRs) received an I-151. The small, green Form I-151 had immediate value in identifying its holder as an alien who was entitled to live and work indefinitely in the United States.
Combating Document Fraud—The Green Card Changes Color
In the early 1950s, the status of being a Green Card holder became so desirable that counterfeit Form I-151s became a serious problem. To combat document fraud, the INS issued 17 different re-designs of the Form I-151 between 1952 and its complete revision in 1977.
In 1964, the color of the Green Card was changed to pale blue. After 1964, it became a dark blue. Regardless of color, the Form I-151 still carried with it the benefits indicated by the term Green Card, and those who wanted, obtained, issued or inspected it continued to refer to it by that name.
During the mid-1970s, INS studied methods to produce a more counterfeit-resistant Green Card. The study resulted in centralized card production at the Immigration Card Facility in Texas. This created standardization and accountability lacking with local card production. In addition, new materials and technologies were introduced to create a new machine-verifiable Green Card. The new Green Card, first issued in 1977, also had a new form number, I-551.
http://www.usa.or.th/news/press/1998/nrot079t.htm