Fort Sheridan was a U.S. Army post named after Civil War cavalry general Philip Sheridan to honor his many services to Chicago from 1868 to 1883. The Commercial Club of Chicago, concerned since 1877 about the need for a military garrison, was motivated by the Haymarket Riot in 1886 to arrange the donation of 632 acres of land to the federal government for that purpose. Troops arrived in November 1887 and were used in 1894 to quell labor unrest during the Pullman strike. Beginning with the Spanish American War in 1898, Fort Sheridan became a mobilization, training, and administrative center. During World War II, more than 500,000 men and women were processed through military service there. Army officers who later became famous, including George Patton and Jonathan Wainwright, lived there. The 94 Historic District buildings, built from 1889 to 1910, include 64 structures that were the first major works of Chicago architects William Holabird and Martin Roche. The earliest buildings were made of bricks molded and fired on site from clay mined from lakefront bluffs. The water tower, originally the tallest structure in the Chicago area, was altered and shortened by 60 feet in 1940, and the row of buildings flanking it served as troop barracks. The 110-acre Historic District was placed on the National Register of Historic Places in 1980, was designated a National Historic Landmark in 1984, and Fort Sheridan closed in 1993.