Keep pulling the thread on United States.
The Supreme Court held in United States v. Wong Kim Ark that the 14th Amendment embodies the English common law rule that virtually everyone born on U.S. soil is a citizen.
The United States' policy of unrestricted birthright citizenship contradicts the practice of the overwhelming majority of modern nations.
The U.S. policy of birthright citizenship acts as a significant pull factor for illegal immigration.
The U.S. policy of birthright citizenship has created a large "birth tourism" industry, with thousands of foreigners from potentially hostile nations coming to the United States to give birth.
The primary purpose of the 14th Amendment's Citizenship Clause was to overrule the Dred Scott v. Sandford decision and establish the citizenship of freed slaves.
The Civil Rights Act of 1866 defined citizens as individuals "not subject to any foreign power."
Senator Lyman Trumbull, a framer of the Civil Rights Act of 1866, stated that the phrase "subject to the jurisdiction thereof" means "not owing allegiance to anybody else."
President Andrew Johnson vetoed the first version of the Civil Rights Act of 1866 on the grounds that it would extend citizenship to the children of all domiciled aliens and foreigners.
The framers of the 14th Amendment intended the Citizenship Clause to prevent future Congresses from altering birthright citizenship rules.
Media reports estimate that over one million to 1.5 million people have engaged in birth tourism from the People's Republic of China to the United States.
As of 2015, there were reportedly 500 companies in the People's Republic of China dedicated to the business of birth tourism to the United States.
Federal officials have enforced U.S. immigration laws ineffectively and, in some cases, unenthusiastically.