Hi Karen! 

You can really go either way with this, as long as you title the materials in a consistent manner. The SAA guide, Describing Archives: A Content Standard, gives this guidance, below, stating that you can use the most recent name and explain the changes in a historical or scope note. Another option is to use the most common form of name, or the name in use during creation of the bulk of the material. 

Best, 

Jennifer 

Corporate body whose name has changed

2.3.17 Where the name of the corporate body has changed, use the last (latest) name of the corporate body represented in the materials being described. Predecessor names of the corporate body may be recorded in the Name of Creator(s) Element as specified in Rule 2.6.7.

University of California, Irvine, Office of Research and Graduate Studies records

These records include those from this same body under two previous names,Graduate Division (1964–1981) and Division of Graduate Studies and Research (1981–1987).

Allied Theatres of Michigan records

These materials include records of this same body under its earlier name,Motion Picture Theatre Owners of Michigan (name changed in 1931). 

2.3.18 Optionally, where the name of the corporate body has changed, use the name under which the bulk of the material was created.