A history of the Pulitzer Prize

From pulitzer.org:

In writing his 1904 will, which made provision for the establishment of the Pulitzer Prizes as an incentive to excellence, [Joseph] Pulitzer specified solely four awards in journalism, four in letters and drama, one for education, and four traveling scholarships. In letters, prizes were to go to an American novel, an original American play performed in New York, a book on the history of the United States, an American biography, and a history of public service by the press.

But, sensitive to the dynamic progression of his society, Pulitzer made provision for broad changes in the system of awards. He established an overseer advisory board and willed it "power in its discretion to suspend or to change any subject or subjects, substituting, however, others in their places, if in the judgment of the board such suspension, changes, or substitutions shall be conducive to the public good or rendered advisable by public necessities, or by reason of change of time." He also empowered the board to withhold any award where entries fell below its standards of excellence. The assignment of power to the board was such that it could also overrule the recommendations for awards made by the juries subsequently set up in each of the categories.

Since the inception of the prizes in 1917, the board, later renamed the Pulitzer Prize Board, has increased the number of awards to 21 and introduced poetry, music, and photography as subjects, while adhering to the spirit of the founder's will and its intent.