Lineage

• Any persons born to at least one U.S. citizen is automatically also a U.S. citizen regardless of the location of birth. When a child is born to an U.S. citizen on foreign soil, the birth should be registered with the nearest U.S. Consulate General in order to receive an American birth certificate. If the birth is not registered, citizenship can be registered anytime during the child's life by filing form N-600 with the United States Citizenship and Immigration Services (USCIS). Lineage also includes grandchildren of U.S. citizens. In such cases, form N-600K must be filed with the USCIS in order to obtain a certificate of citizenship.
  
  

U.S. Soil

• Any child born on U.S. soil (not including children of diplomats) is automatically a U.S. citizen regardless of the parents' citizenship status. A child born to illegal immigrants on U.S. soil is automatically a U.S. citizen even though his parents are not.
  
  

Naturalization

• Aside from gaining citizenship through birth, it is possible to become a citizen through naturalization. Naturalization is a process of learning how to be an U.S. citizen. Naturalized citizens are required to live legally (with a green card) in the United States for five years before being considered ready for citizenship. During the five years, the legal resident must prove that he is a lawful citizen complying both to state and federal laws, that he can financially support himself and his dependents, and actively prove his patriotic intent for assimilating into American society by learning English and basic U.S. civics. A final condition of naturalization is actually being present in the United States. Green card holders cannot be absent from the country for periods of one year or more without obtaining a permit or risk losing either their green card or their citizenship eligibility.
  
  

Marriage

• Citizenship also can be gained through marriage to an U.S. citizen. The path to citizenship in such cases is still naturalization, however, the residential requirement is only three years rather than five. Conditions for citizenship for marriage-based immigrants is that they remain in the marriage they entered the U.S. on or have substantial evidence that the marriage was entered in good faith but ended due to death, domestic abuse, gambling, alcohol, imprisonment or other reasons for nullification.
  
  

14th Amendment

• Regardless of how U.S. citizenship is required, be it lineage, birth on U.S. soil or through naturalization, the 14th amendment of the United States Constitution states that all citizens are treated equally under the same laws and rights. There is no distinction between citizenship once it is acquired.