The Enterprise Railroad Company was a black-owned corporation organized in 1870 to transport freight by horse-drawn street railway between the Charleston wharves and the railroad depot. This seems to have been the only black-owned railroad in U.S. History.
“Several South Carolinians participated in the speculative railroad fever that swept across the South during Reconstruction. Four black South Carolina Representatives—Joseph Rainey, Richard Cain, Alonzo Ransier, and Robert Smalls—partnered with seven others to form the Enterprise Railroad Company in 1870. The small, horse-drawn rail service shipped goods from the wharves on the Cooper River in Charleston to stations farther inland that connected to major cities. The business barely weathered the boom-and-bust economy of the early 1870s. It passed to white ownership in 1873 and lasted until the 1880s.” - Source
Below are two financial documents from the short-lived company.