In 1904, the United States government under Theodore Roosevelt purchased the railway from the French canal company. At the time, railway assets included some of track, 35 locomotives, 30 passenger cars, and 900 freight cars. Much of this equipment was worn out or obsolete and had to be scrapped. The railway cost some US$8 million to build — eight times the initial 1850 estimate — and presented considerable engineering challenges, passing over mountains and through swamps. Over 300 bridges and culverts needed to be built along the route. It was built and financed by private companies from the United States. Among the key individuals in building the railway were William H. Aspinwall, David Hoadley, George Muirson Totten, and John Lloyd Stephens. The railroad was built and originally owned by a publicly traded corporation based in New York City, the Panama Rail Road Company, which was chartered by the State of New York on , and the stock in which would eventually become some of the most highly valued of the era. The company bought exclusive rights from the government of Colombia (then known as Republic of New Granada, of which Panama was a part) to build the railroad across the isthmus. The railway carried significant traffic even while it was under construction, with traffic carried by canoe and mules over the unfinished sections. This had not been originally intended, but people crossing the isthmus to California and returning east were eager to use such track as had been laid. When only of track had been completed, the railway was doing a brisk business, charging $0.50 per mile per person for the train ride and increasing to $25 per person when the line was finally completed. By the time the line was officially completed and the first revenue train ran over the full length of its grade on January 28, 1855, more than one-third of its $8 million cost had already been paid for from fares and freight tariffs. The fare for first-class passage was set at $25 one way, one of the highest rates in existence for a ride. High prices for carrying freight and passengers, despite very expensive ongoing maintenance and upgrades, made the railroad one of the most profitable in the world. Engineering and medical difficulties made the Panama Railway the most expensive railway, per unit length of track, built at the time. It is estimated that from 5,000 to 10,000 people may have died in the construction of the railroad, though the Panama Railway company kept no official count and the total may be higher or lower.