The South Shore Railway started out in 1903 as "The Chicago & Indiana Air Line Railway," traveling between Indiana Harbor and East Chicago. In 1904, the streetcar line was renamed
"The Chicago, Lake Shore and South Bend Railway”. By 1908, "The Lake Shore" stretched across Northwest Indiana and extended 68.9 miles from Hammond to South Bend. The "Lake Shore" passengers enjoyed fast, frequent, comfortable service, and the line quickly became recognized as one of the best in the country. By 1909, "Lake Shore" trains expanded, taking passengers into downtown Chicago.
Competition from steam railroads and the newly popular automobile drained ridership, and "The Lake Shore" went bankrupt. Samuel Insull purchased the railroad at public auction in June, 1925 and renamed it The Chicago South Shore and South Bend Railway. Insull modernized the railway cars and put the railroad into top condition. He purchased new cars, built new stations, and converted the railroad from AC electric system to its current 1500 volt DC system. These changes helped the South Shore become profitable again, but the Great Depression put the South Shore into bankruptcy again in 1933, but was again operating profitably by 1938.
During the Second World War, the South Shore experienced its best years. Ridership climbed to over six million annual passengers during the war years, a record yet to be broken. Trains operated around the clock to move people working in the factories. In 1977, the Indiana General Assembly created the Northern Indiana Commuter Transportation District (NICTD) to rescue the ailing South Shore. The privately held railroad changed ownership in 1984 and five years later was hopelessly in debt and once again bankrupt. The railroad is now in the hands of the public sector and profit is no longer the motivation for providing rail passenger service. NICTD operates the rail service as a public service because the people and economy of Northwest Indiana need an alternative, reliable form of transportation to get to jobs, schools, museums, and recreational opportunities found in the City of Chicago.