In the 1870s and 1880s, and through the 1920s, it's clear that many legislators and judges did not agree that birthright citizenship applied to everyone born in the borders of the US. The modern interpretation is highly debatable.

Additional Reading

"Why the World Is Giving Up on Birthright Citizenship" by Ryan McMaken: https://mises.org/mises-wire/why-world-giving-birthright-citizenship

“Why Birthright Citizenship Is Rare In Europe” by Ryan McMaken: https://mises.org/mises-wire/why-birthright-citizenship-rare-europe

“Don’t Confuse Immigration with Naturalization“ by Ryan McMaken: https://mises.org/mises-wire/dont-confuse-immigration-naturalization

“The Problem with the Arbitrary Line between Legal and Illegal Immigration“ by Ryan McMaken: https://mises.org/power-market/problem-arbitrary-line-between-legal-and-illegal-immigration

Be sure to follow the Loot and Lobby podcast at https://Mises.org/LL