Ex Parte Young creates a legal fiction: when state officials enforce unconstitutional laws, they're stripped of their official status and become ordinary citizens you can sue. The doctrine lets people seek court orders stopping officials from violating federal law, even though the 11th Amendment normally bars suits against states.
The 1908 case arose when Minnesota passed a law slashing railroad rates and imposing severe penalties on railroads that didn't comply. Railroads sued Attorney General Edward Young to stop him from enforcing the law, arguing it was unconstitutional and would cause irreparable harm. The Supreme Court sided with the railroads, establishing that sovereign immunity doesn't protect officials who act illegally. The ruling only allows suits for prospective injunctive relief—court orders stopping future violations. You can't use Ex Parte Young to get money damages for past harms. The Supreme Court has narrowed the doctrine in recent decades, blocking its use when Congress creates detailed enforcement schemes in federal statutes.