On May 1, 1861, the company's title was changed again, this time to the Bethlehem Iron Company. Construction of the first blast furnace began on July 1, 1861, and it went into operation on January 4, 1863. The first rolling mill was built between the spring of 1861 and the summer of 1863, with the first railroad rails being rolled on September 26. A machine shop, in 1865, and another blast furnace, in 1867, were completed. During its early years, the company produced rails for the rapidly expanding railroads and armor plating for the US Navy.