The nation's highest court agrees to review lawsuit questioning citizenship by birth.

The nation's highest court has will hear a landmark case that questions a century-old guarantee: automatic citizenship for individuals born in the United States.

On the inaugural day in office this winter, the President signed an order aiming to terminate the policy, but the action was struck down by the judiciary after lawsuits were filed.

The Supreme Court's eventual ruling will either uphold citizenship rights for the offspring of foreign nationals who are in the US undocumented or on short-term permits, or it will overturn them completely.

Next, the justices will set a time to hear oral arguments between the government and claimants, which involve immigrant parents and their newborns.

A Constitutional Cornerstone

For more than 150 years, the Fourteenth Amendment has established the rule that anyone born in the United States is a American citizen, with exceptions for children born to diplomats and personnel of foreign military forces.

"Anyone born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States."

The challenged executive order sought to refuse citizenship to the children of people who are whether in the US in violation of immigration law or are in the country on short-term status.

The United States belongs to a group of about three dozen nations – primarily in the Americas – that award immediate citizenship to anyone born in their territory.