Market Street's OC (Oldest Car). Built in 1896 by the Hammond Company for the original Market Street Railway as a single truck 2 motor car, the present day historic preservation group Market Street Railway states that "578 is America’s oldest passenger streetcar still on the active roster of an urban transit agency". After continuing to stay on the active roster by serving as a sand car, 578 restored in 1956 for the 50th Anniversary of the 1906 earthquake, was instrumental in the Market Street Trolley Festivals of the 1980s, and in 1987 operated trial runs for the public over the State Belt tracks between the Ferry Terminal and Pier 39 that would eventually be added to SFMTA/San Francisco Municipal Transportation Agency F Line service and extended to Fisherman's Wharf. The car is seen at Pier 39 on Saturday, September 26, 2015 during the annual MUNI Heritage Weekend celebration. After being suspended for over a year due to COVID-19 restrictions and reduced ridership, on Saturday, May 15, 2021, F Line cars return to the streets of San Francisco, California along with a number of other previously suspended and recently improved services.