What is a ‘federal question’? Section two of article three of the Constitution grants jurisdiction to federal courts over, among other items, ‘all cases in law and equity, arising under this Constitution, the laws of the United States, and treaties made … under their authority’. This has become generally known as the grant of ‘federal question’ jurisdiction. The present statute giving such jurisdiction to federal courts dates only from 1875; not only has it been restrictively construed, but existing federal schemes of benefits, rights, and regulations provide us with a familiar, pat, confining notion of the nature of federal questions. What sorts of matters might have been expected to constitute federal questions in 1787, when the Constitution was written, and when such schemes were not contemplated much less established?