Series consists of personal and political material. His personal effects include correspondence with his family in Scotland and memorabilia of Strachan's boyhood (such as badges and certificates earned as a corporal in the 211st Glasgow Company of the Boys' Brigade), and family photographs. Most of Strachan's papers concern his political career, as member of the legislative assembly, and as Leader of the Opposition, and government minister.
These papers were originally arranged by topic and subject, and, as far as possible such arrangement has been maintained. Thus notes and correspondence pertaining to Strachan's constituency have been separated from papers dealing with provincial topics, such as the Columbia River power project. Similarly, papers dealing with the CCF/NDP caucus are distinct from the extensive correspondence that resulted from unrest within the New Democratic Party during the various leadership challenges of the 1960s.