At first, book covers were used merely to protect the pages inside. But as graphic design became a profession in the mid-1800s, publishers found they could use covers for advertising and to promote the contents.
Russian artist Aleksander Rodchenko and English illustrator Aubrey Beardsley were among the most influential early book cover designers, the latter providing artwork for Henry Harland's popular "Yellow Book" series of the 1890s.
Book collectors often cite the 1920s and '30s as the time when cover design began to regularly feature more than a random pattern or colors.
As more writers and publishers emerged during the early 1900s, publishers realized that cover design could, in addition to identifying the subject matter, help push sales of a book.
Hard cover books were manufactured with dust jackets beginning in the late 1800s. These shiny jackets made cover art more noticeable.