Legislative mail appears to have been grouped by year for 1963-1970 (88th through 91st Congresses), then by Congress for the years 1971-1980, so 1971-1972, 1973-1974, etc. This arrangement has been maintained.

Within each year or two-year grouping, there are two subseries. The first, entitled simply Legislative Mail, is arranged alphabetically by committee to which the relevant legislation was assigned and within that by topic. Staff notations on carbons of responses have provided the main guide, but these are not always consistent, e.g. agricultural flooding issues could be noted as either the Agriculture or the Public Works Committee, protection of marine mammals as either Commerce or Interior, and files for such topics may appear in both locations. The second subseries, entitled Legislative Mail - Issues, consists of letters and responses not linked to specific pieces of legislation and is arranged alphabetically by topic.

Letters are intended to be arranged chronologically within folders. Dates are based on the date of the response, if that is stapled on top of the letter, otherwise on the date of the letter, or, in the absence of that, by postmark. If none of those is present, the date of receipt is used, if present, or, as a last resort, the date of the reply if stamped on the letter. In view of many hands working on restoring original order to this series (see Scope and Content note above), inconsistencies may exist.

Topical designations as received have been used where possible, which results in some inconsistences across the files, e.g. Prayer in Schools for one Congress, School Prayer for another. A given piece of legislation may also appear in two different committees, e.g. Genocide Treaty in both Foreign Relations and Judiciary. Also, letters on a topic received belatedly, e.g. the Supreme Court nominations of Clement Haynsworth and Harold Carswell, are filed chronologically and therefore may be separated from the bulk of mail on the topic.