The story
Construction began on April 19, 1851, from Albany to Schoharie Junction, New York, a 35-mile (56 km) stretch that required 12 years to complete. In 1869, the line was extended to Binghamton, lengthening the railroad to 142 miles (229 km).
From Wikipedia’s article on Albany and Susquehanna Railroad, shared under CC BY-SA 4.0.3
