Altoona is a city in western Pennsylvania, located in Blair County about 100 miles east of Pittsburgh. The Pennsylvania Railroad developed the city in 1849 as the point where locomotives would be switched on trains crossing the Alleghenies. The trains crossing the mountains required heavier duty locomotives, which were maintained in Altoona. Two theories exist for the derivation of the name Altoona. One is that it comes from a German town of Altona, now part of Hamburg. The other is that the source is a Cherookee word "allatoona," meaning "high lands of great worth." Fort Roberdeau was built near present day Altoona to defend a lead mine which supplied lead for Washington's Continental Army during the American Revolution. Today, a partial reconstruction can be seen at Fort Robideau Historic Site. In 1849, the Pennsylvania Railroad Company purchased the farmstead of David Robeson, paying him $11,000 for land worth about $2,500 for farming purposes. The first shops were built in 1850 and after the completion of the Horseshoe Curve in 1855, Altoona grew rapidly. Altoona was incorporated as a borough in 1858 and chartered as a city in 1868. During the Civil War, Altoona's importance as a railroad center made it an objective for Confederate forces, but the city was not seriously threatened. It was the site of the Altoona Conference of Union governors in 1863, which endorsed emancipation. In 1864, the first stretch of railroad using steel for the rails was built between Altoona and Pittsburgh. Altoona's four-year university is Penn State Altoona, the outgrowth of the Altoona Undergraduate Center that opened in 1939. The Railroaders Memorial Museum is housed in the former master mechanics building of the Pennsylvania Railroad. The Horseshoe Curve National Historic Landmark was opened in 1992. The Southern Alleghenies Museum of Art specializes in American art of the 19th, 20th, and 21st centuries. Altoona Hospital opened on January 1, 1886, on land donated by the Pennsylvania Railroad in a wooden building that cost less than $17,000.