The American librarian and reformer Melvil Dewey (1851-1931) established the Dewey decimal system of classifying books and played a prominent role in developing professional institutions for librarians.

Melvil Dewey was born in Adams Center, N.Y., on Dec. 10, 1851, the youngest of five children of impoverished parents. His father, a boot maker and keeper of a general store, and his sternly religious mother inculcated principles of hard work and economy in the youth, along with a sense of self-righteousness that marked him throughout his life. He early demonstrated strong mathematical ability and a fascination with systems and classifications. His education was slowed by the need to earn money, and he did not enter Amherst College until he was 19, graduating in 1874.

Dewey worked in the college library during his last 2 years as a student and for the 2 years following his graduation. Although then still attracted to a missionary career, he...