Louis Henry Sullivan (1856-1924) was an American architect and partner in the Chicago architectural firm Alder & Sullivan. He is also known as a mentor to architect Frank Lloyd Wright. The core of the collection is made up of 122 drawings given to Frank Lloyd Wright by Louis Sullivan before Sullivan's death in 1924. The Avery collection represents the bulk of what remains of Sullivan's drawings. Most of the drawings in this collection are designs for ornament representing different stages of Sullivan's stylistic development. Some drawings are annotated by Wright. The collection also includes additional donations of drawings, objects, and papers collected over the years.