The William Allan Neilson collection documents his official duties as President of Smith College. The collection includes correspondence, subject files, organization files, and confidential files. Neilson's collaboration with trustees is demonstrated in the correspondence files. His involvement in the development of the curriculum, alumnae relations, construction of buildings, and the basic running of the college is highlighted in the subject files. Of particular interest in the organization files is information on donors to Smith College. The confidential files document the acquisition of pieces of art for the Smith College gallery.

This collection is organized into four series:

• I. Correspondence
• II. Organization
• III. Subjects
• IV. Confidential