The correct answer is B) Railroads were largely concentrated in the East.
The statement that best describes the state of railroads in the United States immediately following the Civil War is "Railroads were largely concentrated in the East."
That is why with the Pacific Railroad Act of 1862, the federal government authorized the Union Pacific and Central Pacific Railroad companies the construction of the Transcontinental Railroad that connected the East of the United States with the Pacific West. The works started in Sacramento, California to the East and from Omaha, Nebraska, to the West. The works ended in Promontory, Utah when the two railroads connected on May 10, 1869.