Where did the great strike of 1877 occur

Martinsburg, West Virginia

The Great Railroad Strike of 1877, sometimes referred to as the Great Upheaval, began on July 14 in Martinsburg, West Virginia, United States after the Baltimore & Ohio Railroad (B&O) cut wages for the third time in a year. This strike finally ended some 45 days later, after it was put down by local and state militias, and federal troops. Because of economic problems and pressure on wages by the railroads, workers in numerous other cities, in New York, Pennsylvania and Maryland, into Illinois and Missouri, also went out on strike. An estimated 100 people were killed in the unrest across the country. In Martinsburg, Pittsburgh, Philadelphia and other cities, workers burned down and destroyed both physical facilities and the rolling stock of the railroads - engines and railroad cars. Local populations feared that workers were rising in revolution such as the Paris Commune of 1871. At the time, the workers were not represented by labor unions. The city and state governments organized armed militias, aided by national guard, federal troops and private militias organized by the railroads, who fought against the workers. Disruption was widespread and at its height, the strikes were supported by about 100,000 workers. With the intervention of federal troops in several locations, most of the strikes were suppressed by early August. Labor continued to work to organize into unions to work for better wages and conditions. Fearing the social disruption, many cities built armories to support their militias; these defensive buildings still stand as symbols of the effort to suppress the labor unrest of this period. With public attention on workers' wages and conditions, the B&O in 1880 founded an Employee Relief Association to provide death benefits and some health care. In 1884 it established a worker pension plan. Other improvements generally had to await labor organizing.
Date:    July 14 – September 4, 1877
Blockade of engines at Martinsburg, West Virginia, 16 July 1877