正如发明人被授予专利进而可以在有限时间内利用其发明获利，著作人起初也只在相对较短的一段时间内拥有版权 — — 美国规定是自作品首次出版以后的14年。
Just as inventors are given patents so that they can profit from their inventions for a limited time, so, too, authors were originally given copyright for a relatively short period – in the US, it was initially only 14 years from the first publication of the work.