although the enslaved (and their descendants) were not only NOT considered "citizens", but were not even considered "humans" and were instead designated as "property" (i.e., the term "chattel slavery" ).
See "Dred Scott v. Sandford" -
Facts of the case
Dred Scott was a slave in Missouri. From 1833 to 1843, he resided in Illinois (a free state) and in the Louisiana Territory, where slavery was forbidden by the Missouri Compromise of 1820. After returning to Missouri, Scott filed suit in Missouri court for his freedom, claiming that his residence in free territory made him a free man. After losing, Scott brought a new suit in federal court. Scott's master maintained that no “negro” or descendant of slaves could be a citizen in the sense of Article III of the Constitution.
(snip)
Conclusion
7–2 decision for Sanford
MAJORITY OPINION by Roger B. Taney
Held portions of the Missouri Compromise unconstitutional in violation of the Fifth Amendment, treating Scott as property, not as a person.
(snip)
The majority held that “a negro, whose ancestors were imported into [the U.S.], and sold as slaves,” whether enslaved or free, could not be an American citizen and therefore did not have standing to sue in federal court. Because the Court lacked jurisdiction, Taney dismissed the case on procedural grounds.
I expect it would have also covered those illegal European immigrants who were or became indentured servants.
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