Seeing the shortcomings of then-prevalent style of instruction, he combined the ideas of Dewey with his experiences at the Francis W. Parker school to create a progressive education curriculum.
His work caught the attention of Frederic Lister Burk, the president of the San Francisco State Teachers College, who hired him to teach at the institution's affiliated elementary school.
The curriculum included both "common essentials" (reading, writing, number skills, history, and geography) and "creative group activities" such as art, music, literature, and physical education.
[4] Starting in 1928 Washburne led a study, in collaboration with University of Chicago graduate student Mabel Morphett, that attempted to determine the age when a child could reasonably be expected to learn to read.
[10][11] More recent research has suggested that the quality of the instruction a child receives is more important than mental age in determining learning success.
[4] He oversaw the design and completion of the Crow Island School in 1940, which was heralded for its teaching concepts and unique architecture, and is now a National Historic Landmark.
[13] Washburne resigned from the Winnetka School District in 1943 to help the U.S. Army reopen educational facilities in occupied Italy during World War II.
He was the head of the Allied Forces subcommission which revisited the high school scholastic curriculum defined in 1935 by the Italian fascist Minister of Education De Vecchi.