Peter Stenger Grosscup (1852-1921) was a United States federal judge. Grosscup is best remembered for having made use of the judicial injunction against strikers in labor disputes, including most notably the leadership of the American Railway Union in the 1894 Pullman Strike.
Peter S. Grosscup was born in Ashland, Ohio, on February 15, 1852. Grosscup received an A.B. from Wittenberg College in 1872 and an LL.B. from Boston Law School in 1873.
He was in private practice in Ashland, Ohio from 1873 to 1875 and was then city solicitor of Ashland until 1881. He returned to private practice in Ashland from 1881 to 1883, and then in Chicago, Illinois until 1892.
On December 12, 1892, Grosscup was nominated by President Benjamin Harrison to a seat on the United States District Court for the Northern District of Illinois vacated by Henry W. Blodgett. Grosscup was confirmed by the United States Senate on December 20, 1892, and received his commission the same day. According to Almont Lindsey's 1942 book The Pullman Strike, Grosscup received this appointment as political payback for a large donation George Pullman made to the Harrison presidential campaign.
According to Almont Lindsey, federal judges Peter Grosscup and William Woods issued the first omnibus injunction against the Pullman railroad strikers in Chicago protecting 22 railroads on July 2, 1894. This innovative use of a federal injunction charged unnamed strikers with conspiracy for interfering with interstate commerce and the mails thus putting the federal courts at the disposal of corporations to break strikes. The July 3, 1894 New York Times called the injunction a “Gatling gun on paper.”