US Supreme Court will hear legal challenge questioning citizenship by birth.

The nation's highest court has will hear a pivotal case that challenges a century-old guarantee: birthright citizenship for individuals born on American soil.

On the inaugural day in office this winter, the President issued an executive order aiming to halt the policy, but the order was halted by lower courts after constitutional questions were brought forward.

The Supreme Court's ultimate judgment will either support citizenship rights for the children of immigrants who are in the US without authorization or on temporary visas, or it will overturn those rights altogether.

Next, the judges will set a time to hear the case between the administration and claimants, which comprise immigrant parents and their infants.

The Legal Foundation

For over a century and a half, the Constitutional amendment has established the rule that all individuals born in the United States is a American citizen, with specific conditions for children born to foreign diplomats and personnel of occupying armies.

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

The contested presidential order sought to deny citizenship to the offspring of people who are whether in the US illegally or are in the country on non-permanent visas.

The United States is one of about three dozen nations – largely in the Western Hemisphere – that grant instant citizenship to anyone born in their territory.