Atlantic Coast Line Railroad v. Brotherhood of Locomotive Engineers

Congress in 1793, shortly after the American Colonies became one united Nation, provided that in federal courts “a writ of injunction [shall not] be granted to stay proceedings in any court of a state.” Act of March 2, 1793, § 5, 1 Stat. 335. Although certain exceptions to this general prohibition have been added, that statute, directing that state courts shall remain free from interference by federal courts, has remained in effect until this time. Today that amended statute provides:

“A court of the United States may not grant an injunction to stay proceedings in a State court ex*283cept as…