Sub-series 1. Correspondence, 1918-1989, undated

Arranged alphabetically by subject, this sub-series consists of Arnold O. Beckman's personal correspondence files. These files primarily document Beckman's extracurricular activities during his presidency of Beckman Instruments, Incorporated, including, but not limited to his involvement with California Institute of Technology, civic organizations, science organizations, and corporate boards. To a lesser extent, the correspondence files also document some of his professional and business activities, including, but not limited to his faculty duties at Cal Tech, his various consultant jobs with various businesses during the 1930s, and his leadership of National Technical Laboratories. A handful of files containing Beckman's correspondence with individuals are also preserved here.

The contents of the Correspondence files consist mainly of letters. A small amount of accompanying materials, including, but not limited to, speeches, reports, minutes, photographs, clippings, and patents are found in these files as well.