Most of these photos were taken from the back of Amtrak's Pennsylvanian in 2011. The photos of the New York to Washington Line were taken from the back of Amtrak's Crescent in 2008.
New York towards Pittsburgh is considered westward. Philadelphia towards Washington, DC is considered southward, beginning at the Penn interlocking.
On each page, you will see a description such as this:
New York to Washington Line through Philadelphia