Article 3, Section 2, Clause 1

Document 28

Samuel Johnston, North Carolina Ratifying Convention

Gov. Johnston. Mr. Chairman, the learned member from Anson says that the federal courts have exclusive jurisdiction of all cases in law and equity arising under the Constitution and laws of the United States. The opinion which I have always entertained is, that they will, in these cases, as well as in several others, have concurrent jurisdiction with the state courts, and not exclusive jurisdiction. I see nothing in this Constitution which hinders a man from bringing suit wherever he thinks he can have justice done him. The jurisdiction of these courts is established for some purposes with which the state courts have nothing to do, and the Constitution takes no power from the state courts which they now have. They will have the same business which they have now, and if so, they will have enough to employ their time.

The Founders' Constitution
Volume 4, Article 3, Section 2, Clause 1, Document 28
http://press-pubs.uchicago.edu/founders/documents/a3_2_1s28.html
The University of Chicago Press

Elliot, Jonathan, ed. The Debates in the Several State Conventions on the Adoption of the Federal Constitution as Recommended by the General Convention at Philadelphia in 1787. . . . 5 vols. 2d ed. 1888. Reprint. New York: Burt Franklin, n.d.