Research Paper for history of railroads expansion westward.

My thesis/ argument for this research paper is: Why Altoona, Pennsylvania was important for railroads expansion westward in the United States. My paper is about the establishment of the Pennsylvania Railroad in Altoona, PA and I am arguing why without the feat of getting locomotives over the Allegheny Mountains, railroads expansion westward would have been delayed.
Must include an introduction, historiography (using secondary sources), argument (using primary sources), and a conclusion.
Must use endnotes or footnotes when citing.
This research paper must be at least 10 pages long (double spaced).