Arrangement of First Accesion:
The first accession in the 1960s was organized as follows: (1) Administrative (1929-1962) arranged chronologically; (2) Governmental Activities (1942-1965) arranged chronologically; (3), Professional and Personal Material (1927-1966) arranged chronologically; (4) Manuscripts and Publications (1921-1966) arranged chronologically.
Arrangement of Second Accession:
The second accession from 2015 is organized into 6 series (arranged by the University Archives, Midwestern State University, Texas):
Series 1: Personal Material contains personal materials including an autobiography, University of Illinois faculty and committee assignments, fliers, and ledger books and correspondence for Volunteers for Stevenson-Kefauver. Files were arranged by the University Archives, Midwestern State University, Texas.
Series 2: Correspondence and Professional Papers contains correspondence files and papers about educational institutions and journals. These include correspondence from Economic Issues, the Judson King Foundation, and the University of Illinois. Files were arranged by the University Archives, Midwestern State University, Texas.
Series 3: Lecture Notes contains Professor Gray's lecture notes covering monopoly, economic power, economic issues, regulation, government and business relations, and landscape architecture among others. Files were arranged by the University Archives, Midwestern State University, Texas.
Series 4: Manuscripts and Publications contains book and article reviews, and speeches by Horace Gray on topics such as public utilities, monopolies, the American enterprise system, antitrust policies, power production, economic power, public regulation, and investments. Files were arranged by the University Archives, Midwestern State University, Texas.
Series 5: Conferences and Talks contains materials related to conferences Gray attended as well as his presentations and those by other scholars. These meetings discuss economic and social issues such as public utilities, business, education, taxation, rural electrification, economic power, and the League of Women Voters. This series is arranged chronologically.
Series 6: Congressional Hearings contains records from congressional hearings and committees. Horace Gray testified at some of the hearings; also included are his notes. Materials are arranged by U. S. Senate, U. S. House of Representatives, and U. S. Congress and chronologically within.