The nation's highest court agrees to consider legal challenge questioning birthright citizenship.

The top court has will hear a pivotal case that questions a historic constitutional right: birthright citizenship for people born within US borders.

On day one in office this winter, President Donald Trump issued an executive order aiming to end birthright citizenship, but the action was halted by federal courts after lawsuits were brought forward.

The Supreme Court's ultimate decision will ultimately uphold citizenship rights for the offspring of immigrants who are in the US without authorization or on short-term permits, or it will nullify them entirely.

Next, the justices will set a time to hear oral arguments between the federal government and plaintiffs, which include immigrant parents and their infants.

A Constitutional Cornerstone

For nearly 160 years, the Fourteenth Amendment has codified the rule that every person born in the United States is a American citizen, with certain exclusions for children born to embassy personnel and members 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 disputed executive order sought to deny citizenship to the offspring of people who are either in the US illegally or are in the country on short-term status.

The United States is among about 30 countries – largely in the Americas – that award instant citizenship to all those born in their territory.