Final answer:
The exact number of miles of right-of-way track Amtrak owned is not specified in the reference provided. Historical context does elaborately discuss the growth of the railroad network in the United States and federal support through land grants and financial backing.
Step-by-step explanation:
The specific number of miles of right-of-way track that Amtrak owned at one time is not provided in the reference information. However, the reference touches upon historical aspects of railroad construction and the immense land grants given to railroad companies by the federal government, including the Union Pacific and Central Pacific, which were pivotal in creating a transcontinental network. Amtrak, established to consolidate remaining passenger rail lines, is not mentioned with respect to the extent of track ownership.
The development of railroads in the United States was significantly boosted by federal support, with land grants incentivizing the construction of tracks and the consolidation of private rail lines into Amtrak in the 20th century to maintain passenger service. By 1890, there were approximately 180,000 miles of railroads in the nation, far exceeding the amount prior to the Civil War. Financing for the growth of the railroads included private capital, federal and state loans, and land grants, with the federal government granting over 100 million acres to various railroads in the West.