The sentence that can be removed <u>without affecting the explanation</u> is "<em>In the 1800s, the United States was still a very young nation, trying to solidify its identity</em>."
The reason this sentence can be removed is that it does not offer any necessary information to the explanation. The passage is about how technology leads to bigger cities. This information is conveyed just as efficiently without the need for the first sentence.
Rather than serving to offer information, the first sentence in the passage serves as a sort of <u>introduction</u> to the text. The very next sentence can just as easily serve as an intro to the passage while providing context for the development of early technology that led to the industrial revolution.
For these reasons, the sentence "<em>In the 1800s, the United States was still a very young nation, trying to solidify its identity</em>." can easily be removed from the passage <u>without affecting</u> the explanation.
To learn more visit:
brainly.com/question/816588?referrer=searchResults