The nation's highest court agrees to review lawsuit disputing birthright citizenship.

The US Supreme Court has agreed to take on a pivotal case that puts to the test a longstanding constitutional right: guaranteed citizenship for individuals born in the United States.

On the inaugural day in office this winter, the President signed an order aiming to halt this practice, but the action was struck down by the judiciary after legal challenges were filed.

The Supreme Court's ultimate judgment will either support citizenship rights for the children of migrants who are in the US undocumented or on short-term permits, or it will nullify them completely.

Next, the justices will calendar a session to hear the case between the government and plaintiffs, which include parents who are immigrants and their infants.

A Constitutional Cornerstone

For over a century and a half, the 14th Amendment has established the doctrine that anyone born in the nation is a citizen, with exceptions for children born to embassy personnel and members of invading forces.

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

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

The United States is one of about three dozen nations – mostly in the North and South America – that provide automatic citizenship to any person born on their soil.