Wallace Stevens on The Poetry Foundation
https://www.poetryfoundation.org/poems-and-poets/poets/detail/wallace-stevens
Links to many poems, with a detailed biography.
On "Of Modern Poetry"
http://www.english.illinois.edu/maps/poets/s_z/stevens/modern.htm
An excellent introduction to relevant criticism on "Of Modern Poetry," presented as a series of excerpts. From the University of Illinois MAPS project, a database on Modern American poetry.
The Patron Saint of Inner Lives
https://www.theatlantic.com/magazine/archive/2016/04/the-patron-saint-of-inner-lives/471468/
An excellent biographical article on Stevens that offers insight into his inner life, his profession, and his process of composition.
Insurance Man: The Thrilling Mind of Wallace Stevens
http://www.newyorker.com/magazine/2016/05/02/the-thrilling-mind-of-wallace-stevens
An insightful and detailed article on Stevens that functions as a review of Paul Mariani's book The Whole Harmonium: The Life of Wallace Stevens.
Marianne Moore on Wallace Stevens
http://www.nybooks.com/articles/1964/06/25/on-wallace-stevens/
Recollections and thoughts on Wallace Stevens by fellow modernist poet Marianne Moore.
Talk with Mr. Stevens
http://www.nytimes.com/books/97/12/21/home/stevens-talk.html
A 1954 New York Times interview with Wallace Stevens.
The Poetry of World War I
https://www.poetryfoundation.org/articles/70139/the-poetry-of-world-war-i
A poetry sampler compiled by The Poetry Foundation of poems written during, and in response to, World War I, including chronology of the war and relevant timeline information. For contextual background on the literary environment during the early years of Modernism.
The Poetry of World War II
https://www.poetryfoundation.org/articles/91359/the-poetry-of-wwii
A poetry sampler compiled by The Poetry Foundation of poems written during, and in response to, World War II, including chronology of the war and relevant timeline information. For contextual background on the literary environment during the years when Stevens published Parts of a World.