In 1866, the author of the 14th Amendment –Senator Jacob M. Howard of Michigan – explained and clarified it's purpose. Here's what he said...

Howard wrote “that every person born within the limits of the United States, and subject to their jurisdiction, is by virtue of natural law and national law a citizen of the United States. This will not, of course, include persons born in the United States who are foreigners, aliens, who belong to the families of ambassadors or foreign ministers accredited to the government of the United States, but will include every other class of persons.”