The correspondence covers a wide variety of topics related to his personal, civic, political,and business affairs. Some correspondence deals with those topics of material in London's subject files, such as the files, on churches, mills, racial integration, and the Washington Bicentennial celebration. Many letters contain informational material, which London apparently used in his newspaper articles, speeches, and histories. Notable correspondents include Governors Morrison, Hoey, Broughton, Cherry, Umstead, Hodges, and Sanford, Senators Furnifold M. Simmons and Josiah Bailey, and Congressmen A. Paul Kitchin and Charles R. Jonas. There are a number of letters from political leaders at the state level, R. Hunt Parker, I. Beverly Lake, H. Cloyd Philpott, Clifton Blue, Thad Eure, and many others. There are letters from many well-known editors and educators in North Carolina, such as Josephus and Jonathan Daniels, Harold Tribble and Edward K. Graham. Of particular interest is an autograph letter from Senator Josiah W. Bailey to London discussing the state of world affairs and the extent to which the United States should participate in the events leading to World War II (Sept. 16, 1939).

A number of letters between London and several North Carolina congressmen concern the Truman-MacArthur controversy in April and May, 1951. Another group of correspondence relates to the issues and events concerning the gubernatorial campaign and election of 1960. Letters to London from liberal Raleigh minister W. W. Finlator, and conservative television news editor Jesse Helms reveal the political bitterness and strife resulting from the campaign. There are also copies of letters from London to Richard M. Nixon telling him of the support for him in Richmond County in the 1960 election (April 25, 1963), and to George C. Wallace congratulating him on his statements at a news interview (June 3, 1963).

Isaac London collected some materials in his capacity as chairman of the Richmond County Board of Elections. These include a number of original returns and abstracts of votes from various Richmond County precincts for the 1938 primary election. There are vote tabulations for Richmond County elections, 1918-1924. There is also a poll book (1936-1938), and a registration book, n.d.

Many of the subject files were apparently kept for use as background and informational material for articles which London published in the . The files contain related correspondence, notes, rough copies of the articles, loose and bound clippings, and miscellaneous materials used. The majority of the subject files concern the history and present-day affairs of Rockingham and Richmond County, but some material is broader in scope.

Isaac London was interested in genealogy and compiled information of this kind relating to many of the families of Richmond County. Much of this material was published in the . This collection includes some of his genealogical files, which are arranged alphabetically by name of family, with separate folders for lists of wills, deaths, and marriages.

Isaac London, Jr. served in World War II, but was granted a medical discharge when he contracted a kidney infection. This infection recurred shortly after he entered the University of North Carolina in 1947, causing his death. The collection includes a number of letters (1939, 1945-1947) from Isaac, Jr. to his father from his army base in Mississippi, and many of these give interesting accounts of life in the military during this period. There are a number of letters of sympathy sent to Mr. London upon the death of his son, which are bound in a separate notebook. Other materials of Isaac London, Jr., include a scrapbook, pictures, and miscellaneous items.

The Isaac London Collection also includes account books and subscription books of the . There is an account subscription book for the , the Rockingham newspaper.

The collection contains a large number of pamphlets and booklets. Included are: , by Rev. Jos. Blount Cheshire; , by Capt. S. A. Ashe; , by the Literary and Historical Society, 1904; , and a group of pamphlets containing the judicial decisions of Chief Justice Walter Clark. Sixteen pamphlets relate to various aspects of Rockingham and Richmond County life, including the Richmond County Fair Association pamphlets, a 1923 Rockingham city directory, and other miscellaneous pamphlets.

Among the miscellaneous items in the collection are biographical sketches of London and his father; an article by Kemp P. Battle, in manuscript form, entitled ; articles by London on various old cemeteries in Richmond County including a list of persons buried in the Stewartsville cemetery; a copy of the original act of incorporation of the town of Rockingham; a copy of J. Melville Broughton' s speech announcing his candidacy for governor: a list of Richmond County widows receiving Civil War pensions; an article by London concerning the Red Shirts of Richmond County led by Cameron Morrison and W. N. Everett (1898); an article by Fred A. Olds on early North Carolina laws; a speech by Secretary of State W. N. Everett before the State Democratic Convention, 1924; and many other items concerning Richmond County history.