20th-century American historians

Walter Henry Breen Jr. (September 5, 1928 – April 27, 1993) was an American numismatist, writer, and convicted child sex offender as well as the husband of author Marion Zimmer Bradley. He was known among coin collectors for writing Walter Breen's Complete Encyclopedia of U.S. and Colonial Coins. "Breen numbers", from his encyclopedia, are widely used to attribute varieties of coins. He was also known for activity in the science fiction fan community and for his writings in defense of pederasty as a NAMbLA activist.

James Wesley Silver (June 28, 1907 – July 25, 1988) was a history professor and author. He wrote Mississippi: The Closed Society. He was a professor at the University of Mississippi, then University of Notre Dame, and finally at the University of South Florida. He was targeted for firing despite his tenure at Ole Miss because of his support for civil rights.When rioting erupted on the Ole Miss campus after James Meredith became the University of Mississippi's first African-American student and federal troops moved in to keep order, Silver befriended Meredith. In a speech to the Southern Historical Association in the Fall of 1963, he analyzed the violence with which Mississippi was resisting desegregation. Mississippi was, he said, "a closed society" -- "totalitarian," "monolithic," "corrupt." The speech received widespread media coverage, and he expanded his analysis in a book, Mississippi: The Closed Society (1964). His advocacy of racial change had subjected him to hostility in Mississippi and even an attempt by the Mississippi State Sovereignty Commission to have him fired. That effort failed, but Silver took a job teaching at University of Notre Dame in Indiana.He taught at Notre Dame from 1965 until 1969. He left Notre Dame to teach history at the University of South Florida until he retired in 1982.He corresponded with the president of Tougaloo College A. D. Beittel.Photographer Martin J. Dain took photographs of him in Oxford, Mississippi. Silver was a member of the American Academy of Arts and Sciences.

James Thomas Flexner (January 13, 1908 – February 13, 2003) was an American historian and biographer best known for the four-volume biography of George Washington that earned him a National Book Award
in Biography and a special Pulitzer Prize. His one-volume abridgment, Washington: the Indispensable Man (1974) was the basis of two television miniseries, George Washington (1984) and George Washington II: The Forging of a Nation (1986), starring Barry Bostwick as Washington.

Hendrik Willem van Loon (January 14, 1882 – March 11, 1944) was a Dutch-American historian, journalist, and children's book author.

Randy Shilts (August 8, 1951 – February 17, 1994) was an American journalist and author. After studying journalism at the University of Oregon, Shilts began working as a reporter for both The Advocate and the San Francisco Chronicle, as well as for San Francisco Bay Area television stations. In the 1980s, he was noted for being the first openly gay reporter for the San Francisco Chronicle.His first book, The Mayor of Castro Street: The Life and Times of Harvey Milk, was a biography of LGBT activist Harvey Milk. His second book, And the Band Played On, chronicled the history of the AIDS epidemic. Despite some controversy surrounding the book in the LGBT community, Shilts was praised for his meticulous documentation of an epidemic that was little-understood at the time. It was later made into an HBO film of the same name in 1993. His final book, Conduct Unbecoming: Gays and Lesbians in the US Military from Vietnam to the Persian Gulf, examined discrimination against lesbians and gays in the military.
Shilts garnered several accolades for his work. He was honored with the 1988 Outstanding Author award from the American Society of Journalists and Authors, the 1990 Mather Lectureship at Harvard University, and the 1993 Lifetime Achievement Award from the National Lesbian and Gay Journalists' Association. Diagnosed with HIV in 1985, Shilts died of an AIDS-related illness in 1994 at the age of 42.

Felix Gilbert (May 21, 1905 – February 14, 1991) was a German-born American historian of early modern and modern Europe.
Gilbert was born in Baden-Baden, Germany, to a middle-class Jewish family, and part of the Mendelssohn Bartholdy clan. In the latter half of the 1920s, Gilbert studied under Friedrich Meinecke at the University of Berlin. Gilbert's area of expertise was the Renaissance, especially the diplomatic history of the period He was a fellow of the Institute for Advanced Study in Princeton from 1962 to 1975, and maintained an active involvement as an emeritus faculty member until his death in 1991. He was elected to the American Academy of Arts and Sciences in 1963 and the American Philosophical Society in 1969.The main reading room of the German Historical Institute in Washington, D.C. is named in his honor.

George Alfred Leon Sarton (; 31 August 1884 – 22 March 1956) was a Belgian-American chemist and historian. He is considered the founder of the discipline of the history of science as an independent field of study. His most influential works were the Introduction to the History of Science, which consists of three volumes and 4,296 pages and the journal Isis. Sarton ultimately aimed to achieve an integrated philosophy of science that provided a connection between the sciences and the humanities, which he referred to as "the new humanism".