William (Will) Braasch Watson of Concord and Chilmark died at the Martha’s Vineyard Hospital on August 13. He was 89 and one day shy of his 90th birthday.

The underlying cause of his death was Parkinson’s disease, which was diagnosed in 2006.

He was born in Rochester, Minn. and raised in Pittsburgh, Pa. He attended Phillips Academy Andover, graduated from Haverford College in 1954, and received a doctorate in history from Harvard. He taught history at the Massachusetts Institute of Technology (MIT) for 45 years, retiring in 2005.

At Haverford he developed a deep commitment to Quakerism. He shared this belief with his first wife, Patricia von Hofsten Price, whom he met and married during his college years. They raised four children together, separated in 1975 and later divorced.

In 1988, he and Myra Harrison married on the Vineyard.

After receiving a Fulbright to study in Spain, his research interests turned from medieval to modern Spain, particularly the Spanish Civil War and Ernest Hemingway’s involvement with it. Among other efforts, he edited Hemingway’s dispatches as a wartime journalist and closely researched the writer’s wartime pursuits, including a secret trip behind enemy lines that he believed Hemingway took to study demolition activities.

At MIT, he developed some unusual and popular courses including a seminar on anarchism and one for the writing program about the Hemingway short story. Starting in 1989, he and Myra served for 16 years as housemasters at Baker House, the famous dormitory designed by Alvar Aalto. They relished their interactions with the undergraduates. He led a project to restore the Aalto furniture still in the dormitory and helped influence MIT to restore and update Baker house in time to celebrate its fiftieth anniversary in 1999.

Will loved the Vineyard and had visited every summer since 1986. He first sailed its waters in his large ketch and later downsized to a Herreshoff 12 1/2 on Menemsha Pond.

Will is survived by wife Myra Harrison; children Peter, Sarah, Sterling and Gabrielle Watson; and four grandchildren.

He was interred privately at Mt. Auburn Cemetery in Cambridge. A memorial gathering at Cambridge Friends Meeting will be held at a future time.