The Williams Papers span the period 1836 to 1947 with the bulk dating from 1904 to 1942. The collection contains the following series: Diaries and Reminiscences; Correspondence; Subject Files; Legal Papers; Financial Papers; Writings and Speeches; Miscellaneous; Clippings; Printed Material; and Pictures. Correspondence comprises the majority of the collection and particularly focuses on Williams's professional career during the period from 1910 to 1925 when he was editor of the and the While the collection documents aspects of Williams's personal and professional life from his college days through the early 1940s, the last twenty years of his life are not included. There is as well very little information about the Teapot Dome Affair in the correspondence, which occurred during the period covered by the collection.

Williams wrote, spoke, and accumulated material about a variety of topics and concerns which are represented in different parts of the collection. Among the most prominent are Aviation and the Presidential Elections of 1916, 1920, and 1924 which are found in the Correspondence, Subject Files, Writings and Speeches, Clippings, Printed Material and Pictures Series; Military preparedness before the entry of the United States into World War I in the Correspondence, Subject Files, Writings and Speeches, and Pictures Series; Arizona's efforts to achieve statehood in the Correspondence, Legal Papers, and Writings and Speeches Series; Massachusetts politics in the Diaries and Reminiscences, Correspondence, Writings and Speeches, Clippings, and Printed Material Series; and Peace and disarmament in the Correspondence, Subject Files, Clippings and Printed Material Series. Prominent politicians such as Warren G. Harding and Herbert Hoover are represented in the Correspondence, Writings and Speeches, and Clippings Series. The collection would be of interest to researchers studying the League of Nations, the Republican Party during the first quarter of the 20th century, and the political and social climate in Greenville, S.C..

The Correspondence Series illustrates that as a leading spokesman for the Republican Party, Williams corresponded with many public figures concerning the topics above. After moving to Tucson, Williams became involved in Arizona's efforts to become a state. He represented the positions taken by President Taft and expressed these viewpoints in numerous editorials related to political matters. Many letters criticize Woodrow Wilson and Josephus Daniels for their policies relating to military preparedness and foreign relations. Of particular note are Williams's strong opposition to the League of Nations and his correspondence in the collection with leading opponents of the League, including Henry Cabot Lodge (1850-1924), William Edgar Borah, Hiram Warren Johnson, and Frank Bosworth Brandegee.

Also included in the Correspondence Series is extensive family correspondence containing material about the social life and political affairs in Greenville, S.C., where Williams's father was mayor, and about his mother's family, the McBees of Lincolnton, N.C. Numerous letters were written by his uncles, Silas McBee, a noted Episcopal clergyman and editor in New York; William Ephraim Mikell, Dean of the Law School at the University of Pennsylvania; and William Alexander Guerry, an Episcopal bishop in South Carolina. There are also letters from cousins, Mary Vardrine McBee, who founded Ashley Hall, a school for girls in Charleston, South Carolina, and Alexander Guerry, who served in various positions at the University of Chatanooga and at The University of the South. Other correspondents in the series include William Howard Taft, Leonard Wood, Nicholas Murray Butler, Albert J. Beveridge, Calvin Coolidge, Frank H. Hitchcock, Charles Nagel, Theodore Roosevelt, and John Wingate Weeks.

Related collections include the Vardry Alexander McBee Papers at Duke University, the Silas McBee and the McBee Family collections at the University of North Carolina at Chapel Hill, the James Thomas Williams (1845-1936) Papers at the University of South Carolina, and an interview with Williams in the Biographical Oral History Collection at Columbia University.