On Monday, President Donald Trump signed an executive order that will eliminate automatic citizenship for children born in the U.S. to foreign parents, regardless of their immigration status.

On Tuesday, a group of 18 states filed a lawsuit against Trump and federal agencies in a U.S. District Court in Massachusetts, arguing that the order is unconstitutional. The American Civil Liberties Union (ACLU) also initiated a separate legal challenge in New Hampshire on behalf of organizations advocating for immigrant rights on similar grounds.

They assert that this change could undermine a fundamental principle of the United States: that anyone born on American soil is a citizen.

The order, titled “Protecting the Value and Meaning of American Citizenship,” aims to stop federal agencies from issuing Social Security numbers, passports, or welfare benefits to U.S.-born children. This represents a significant reinterpretation of the 14th Amendment, which ensures citizenship for anyone born in the United States.

The order is expected to take effect in mid-February but may face legal obstacles.

Aside from the children of foreign diplomats, all individuals born in the U.S. are currently guaranteed citizenship, commonly referred to as “birthright citizenship,” under the 14th Amendment.

According to Trump’s directive, starting February 19, babies born in America will need at least one parent who is either a U.S. citizen or a lawful permanent resident to obtain citizenship.

This executive order fulfills a long-standing promise made during Trump’s presidential campaign, which has been a focal point for far-right groups advocating for reduced immigration and restricted immigrant rights.

The Center for Immigration Studies, a right-leaning think tank, estimated in 2018 that approximately 300,000 babies are born annually in the U.S. to mothers without legal residency, asserting that these children contribute to a tax burden. This organization, identified as a hate group by the Southern Poverty Law Center, has called for the Supreme Court to address the issue once more.

On Tuesday, the ACLU filed a lawsuit on behalf of groups representing individuals whose children would be affected by the new order.

“Withholding citizenship from U.S.-born children is not only unconstitutional; it’s a harmful rejection of American principles,” stated Anthony Romero, the ACLU’s executive director.

“This directive echoes one of the darkest chapters in American history,” he added, “by crafting a permanent underclass of individuals born in the U.S. who lack full rights as citizens.”

The Story of Birthright Citizenship: A 150-Year Overview

In the United States, birthright citizenship has a long and complex history, often intertwined with the country’s challenging racial issues.

The 14th Amendment was introduced as a reaction to the U.S. Supreme Court’s Dred Scott decision in 1857, which stated that an enslaved or formerly enslaved person could never be recognized as a U.S. citizen. Many scholars believe this ruling heightened tensions leading to the Civil War, which ignited in 1861, just four years later.

Congress adopted the 14th Amendment in 1866, and it was ratified by three-fourths of the states in 1868, in the aftermath of the war.

The amendment’s opening line guarantees the right of citizenship at birth: “All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.”

A court case soon challenged whether this amendment also granted birthright citizenship to the children of immigrant parents born in the U.S. In the case of United States v. Wong Kim Ark, a man born in San Francisco to Chinese immigrants contested the government’s assertion that he was not a citizen.

In 1898, the Supreme Court ruled that “children born in the U.S. to immigrant parents are citizens, regardless of their parents’ immigration status,” as noted by the American Immigration Council.

Guerline Jozef, the executive director of the Haitian Bridge Alliance, stated that abolishing birthright citizenship could lead to a “subclass of individuals who would be stateless,” with no country to identify with.

She noted that hundreds of thousands of Haitians have sought refuge in the U.S. due to political turmoil and violence in their homeland, and their future children could lose their rights under this executive order.

“The consequences are devastating,” she explained. “The critical question for America is: Is this the path we wish to pursue? Are we prepared to strip U.S.-born individuals of their dignity and humanity? This is precisely the outcome that would occur.”

Lauren Villagran contributed to this article