The opinion was written by Judge Joseph Story, who set forth four factors that are in use today, and were ultimately codified in the Copyright Act of 1976 as 17 U.S.C. § 107.

The Reverend Charles Wentworth Upham, a writer and anthologist, had copied 353 pages from the plaintiff's 12-volume biography of George Washington in order to produce a separate two-volume work of his own.

If so much is taken, that the value of the original is sensibly diminished, or the labors of the original author are substantially to an injurious extent appropriated by another, that is sufficient, in point of law, to constitute a piracy pro tanto.This holding effectively expanded copyrightable subject matter significantly, by permitting derivative works to be considered one of the rights of the copyright holder.

In so doing, the court set forth four factors: the "nature and objects of the selections made" (today characterized as the "purpose and character of the use"); the "quantity and value of the materials used" (described today as two factors: the nature of the original work, and the amount taken); and "the degree in which the use may prejudice the sale, or diminish the profits, or supersede the objects, of the original work".

Although its formulation in Section 107 tracks very closely the iterations in modern case law, the factors themselves are essentially the same as set forth by Judge Story in 1841.