Consists of selected correspondence (1885-1887) of Irish writer William Allingham and twenty-seven letters (1892-1916) by his wife, watercolorist Helen Paterson Allingham, to artist William George Daffarn.

Consists of selected papers of classics professor William A. Packard.

Consists of a group of military records collected by Captain William A. Prickitt (1839-1929) documenting the daily operations of African American soldiers in Company G of the United States Colored Infantry's 25th Regiment during the final year of the American Civil War.

Consists of papers of American naturalist William Beebe, primarily relating to his association with the New York Zoological Society (NYZS).

Consists of correspondence and obituaries of the nineteenth-century English poet, painter, and art critic William Bell Scott. He was a friend of Dante Gabriel Rossetti and was accepted by the Pre-Raphaelites.

Consists of papers of William Berryman Scott (Princeton Class of 1877), an eminent vertebrate paleontologist and professor of geology at Princeton University.

William Burgess (1857-1929) was a prominent lobbyist and figure in the United States pottery industry around the turn of the century. The William Burgess Papers document Burgess' tenure on the U.S. Tariff Commission.

William Byler was Executive Director of the Association on American Indian Affairs (AAIA) from 1962 to 1980. After leaving AAIA, Byler continued advocating for the Native American community, first at Gerard, Byler and Associates and later at William Byler Associates. Byler's papers document his work on behalf of the Native American community after leaving AAIA. The papers include legal memoranda, draft and final agreements between Native American communities and companies or government agencies, and court documents, as well as topical files of related legislation and reports on the issues.

Willam Churchill De Mille (1878-1955) was an American playwright, producer, and lecturer. The William C. and Cecil B. De Mille Collection consists of playscripts by William, and some co-authored by his younger brother Cecil.

William C. Trimble, Princeton University Class of 1930, was a career diplomat, serving as United States ambassador to Cambodia (1959-1962) and Deputy Assistant Secretary of State for African Affairs (1965-1968) as well as serving in Brazil and Germany. The collection contains correspondence, speeches, newspaper clippings, photographs, and assorted memorabilia documenting Trimble's career.

William Charles Macready (1793-1873) was an English actor and theater manager. The collection consists of selected correspondence, letters written by members of his family, and some letters, articles, and miscellaneous documents about him. A significant number of letters (45) are from Macready's friend, William Frederick Pollock.

Consists chiefly of correspondence of British musicologist William Charles Smith related to music and to George Frederic Handel.

William Churchill Houston was a professor at the College of New Jersey (now Princeton University), a lawyer, and a statesman. He was a New Jersey delegate to the Continental Convention and the Continental Congress. The collection documents his legal career and his tenure as receiver for Continental taxes in New Jersey.

Consists primarily of correspondence betwen American tea merchant William Couper and his family during the years (1831-1844) when he was traveling abroad to Europe and the Far East.

The collection consists of documents, correspondence, photographs, and other papers of William Courtenay (1832-1901), an English settler, veteran of the American Civil War, and frontier businessman who held positions in the United States Department of the Interior as postmaster, clerk, and Indian Agent at Fort Berthold, Dakota Territory, from 1874 to 1882. These materials document conditions at the Fort Berthold Indian Reservation and are of particular interest for their documentation of frontier transactions, corruption and mismanagement within the reservation system, and the relationships between the people of the Three Affiliated Tribes (Mandan, Hidatsa, and Arikara), the Sioux people, and white settlers.

William Chapin Seitz (1914-1974) was an art historian, painter, and museum curator who received the first PhD in modern art from Princeton University in 1955. The collection consists of ten notebooks Seitz kept for his early courses on ancient art and architecture in Princeton University's Department of Art and Archaeology in 1949 and 1950.

Consists of correspondence between British journalist and critic William Davenport Adams and well-known British authors and poets.

Consists of correspondence and selected manuscripts of the American critic, novelist, poet, and playwright William Dean Howells.

Consists of manuscripts of four works by English novelist William De Morgan.

Consists of about a hundred autograph letters by nineteenth-century British politicians, clergymen, and men of letters to clergyman and reformist William Denton.