Article 1, Section 8, Clause 8
Document 10
Levi Lincoln, Patents for Inventions
26 May 18021 Ops. Atty. Gen. 110The authority given by law to grant patents is unquestionably confined to the citizens of the United States. The privilege is a monopoly in derogation of common right, and, as it is not, ought not to be extended to foreigners. Were it to be, it would be subject to endless abuses, privations, and embarrassments to our citizens. I have no doubt on the question.
The Founders' Constitution
Volume 3, Article 1, Section 8, Clause 8, Document 10
http://press-pubs.uchicago.edu/founders/documents/a1_8_8s10.html
The University of Chicago Press