The sentence that is an example of a sentence fragment is the following one: Thomas Paine's Common Sense, which was published in 1776.
Sentence fragments are a group of words which put togeter look like sentences but are not. In order to be a sentence, a group of words must have an independent clause at least. Independent clauses are sentences that have a subject and a predicate and that can stand on their own because they represent a complete thought. For instance, take A.
A) I like dancing on Saturday nights
On the contrary, sentence fragments do not have independent clauses. They are dependent clauses or phrases. Fragments may look like sentences since they may have a subject and a predicate but they do not represent a complete thought.
The sentence in question is a sentence fragment because it is not a complete thought and therefore it is not an independent clause and cannot stand on its own. A relative clause has been introduced, but the main sentence is not finished, it has the subject but it lacks the predicate.
