This is a common question many newcomers ask upon their 1st encounter with a rare newspaper from nearly every era (Revolutionary War , Civil War , Old West , and even Birthday/Day-You-Were-Born  issues, to name a few). Whether it is the rough left spine present from the issue being removed from a larger volume, or the consecutive numbering which results in only the first issue printed during the year to have a “page 1”, a novice’s immediate (and logical) reaction is that the issue must have come from a book and therefore must be a reprint. However, the truth is actually the opposite. Such signs are good indicators that the issue is likely authentic. To understand this, what is needed is a knowledge of how historic newspapers and magazines were handled up to as late as the 1960’s.
Many publishers of early newspapers started numbering their pages from 1 at the start the year and continued with the consecutive numbering throughout the year. This made it very easy to reference content. Examples of early well-known titles which did this are Harper’s Weekly , The War , Gentleman’s Magazine , Niles’ Register , and Leslie’s Illustrated , to name a few. Although this gave the newspapers a book effect, early readers would not have given this another thought. As far as the spine residue/disbinding evidence (which gives the appearance that the issue came from a book) is concerned, nearly every institution which held rare newspapers  bound them together at the end of each year for protection & permanent storage in libraries. Almost all newspapers through the 1960’s were held in this manner. Your local library likely holds its early newspapers in this form. Two resources which may alleviate any concerns you might have related to this issue are the Library of Congress’ Newspaper Division  & the American Antiquarian Society . HistoryBuff.com  also provided additional information regarding this topic.