Philip Roth, the Pulitzer Prize-winning novelist, quietly arranged to give at least $2 million of his estimated $10 million estate to the Newark, N.J., public library before his death last year.

Friends say he intended his bequest to aid not just the library but the struggling city, where he grew up and which featured prominently in his writing. Before he died, the Newark Public Library announced that Mr. Roth had decided to give it his personal book collection. But his accompanying financial donation—and the plans for its...