The buildings comprising Underground Atlanta were constructed during the city's post-Civil War Reconstruction Era boom, between 1866 and 1871, when the city's population doubled from 11,000 to 22,000 residents. In 1869, the Georgia Railroad Freight Depot was completed to replace the one destroyed by Sherman's troops in 1864. The Georgia Railroad depot, which stands at the entrance of Underground Atlanta, remains the oldest building in downtown Atlanta. Although the depot was originally three stories tall, the second and third story were destroyed by fire in 1935. Besides the train station, the bustling district included hotels, banks, law offices, and saloons. An electric streetcar was installed in 1889 to points South, and by 1900 the depot was serving 100 trains per day with direct service between Atlanta and New York City; Cincinnati, Ohio; Chattanooga, Tennessee; Knoxville, Tennessee; Augusta, Georgia; Macon, Georgia; and Columbus, Georgia.