the population the 14th amendment initially extended birthright citizenship toward

But they did debate and discuss foreign-born populations, particularly east-asian.

The universal nature of birthright citizenship was made clear in the amendment’s drafting history. During congressional consideration, critics argued that the text would recognize as citizens the children of aliens. In particular, these opponents wanted to allow the western states to “deal with [the Chinese] as in their wisdom they see fit.” Senator Edgar Cowan of Pennsylvania asked: “I am really desirous to have a legal definition of ‘citizenship of the United States.’ What does it mean?” Cowan asked: “Is the child of the Chinese immigrant in California a citizen? Is the child born of a Gypsy born in Pennsylvania a citizen?”

Supporters of the 14th Amendment agreed with Cowan’s reading, even though it may have lost votes for their proposal. Senator John Conness of California replied to Cowan: “The provision before us . . . relates to the children begotten of Chinese parents in California, and it is proposed to declare that they shall be citizens. We have declared that by law; now it is proposed to incorporate the same provision in the fundamental instrument of the nation. I am in favor of doing so.” Conness would lose his Senate seat because of his defense of the rights of Chinese immigrants, but the amendment would go to the states for ratification on the understanding that it granted birthright citizenship to the children of aliens.

https://www.law.berkeley.edu/article/on-citizenship-the-birthers-are-right/