Births to Unauthorized Immigrants

From Pew:

About 250,000 babies were born to unauthorized immigrant parents in the United States in 2016, the latest year for which information is available, according to a new Pew Research Center analysis of government data. This represents a 36% decrease from a peak of about 390,000 in 2007. 

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The number of babies born to unauthorized immigrant parents represented about 6% of the 4.0 million total births in the U.S. in 2016, compared with 9% of all births in 2007.

Birthright citizenship derives from the 14th Amendment to the U.S. Constitution, adopted in 1868, which grants citizenship to anyone born in the U.S. The provision has long been interpreted to apply to U.S.-born children regardless of the immigration status of their parents.