Beneath the Streets of New York
At 2 p.m., on October 27, 1904; thousands  of New York City residents poured into the streets of Manhattan. Their cheers competed with the blare of ferryboat horns and the whistle of power plants. The city was celebrating an incredible engineering feat;  the completion of the first section of the New York City Subway. 
The original subway line was 9.1 miles long and had twenty-eight stations. [A] The first train took twenty-six minutes to complete the route, which ran from City Hall to West 145th Street in under a half an hour . Tens of thousands of New Yorkers could now avoid traffic jams by traveling underneath the streets . [B]
As early as 1865, there had been proposals for a New York subway, but that  took decades to resolve the many political, financial, and technical challenges. The engineer, William Barclay Parsons  accepted responsibility for overseeing this project.
Parsons decided that most of the subway tunnel would be constructed using an innovation engineering  method known as “cut and cover.” [C] First, workers used picks and shovels to remove roads and dig a deep trench. After installing wooden braces to hold back the earth, workers built a concrete floor. Tunnel walls were created: with  layers of brick, ceramic blocks, tar-soaked felt for waterproofing, and concrete. The roof was made from arch shaped wooden molds also covered with concrete. Next, track beds were filled with crushed stone, and rails were secured to wooden ties. Finally, the roof was covered with tar-soaked felt, and the roads were rebuilt.
Brightly lit stations welcomed the public, many of them  were skeptical of traveling underground. [D] It didn’t take long for New Yorkers to adapt, however. The day after the subway opened, one newspaper reported that the riders were emerging from underground “having finished what will be to them the daily routine of the rest of their lives.”
18. The writer is concerned about the level of detail in the preceding sentence and is considering deleting the phrase “the first section of” from it. If the writer were to make this deletion, the paragraph would primarily lose information that:
F. reveals how expansive the New York City Subway would become.
G. clarifies that only part of the subway system had been completed by October 27, 1904.
H. makes clear that by October 27, 1904, construction of the second section of the subway was already underway.
J. provides evidence that New York City residents at this celebration believed the entire subway system was complete.