His debut poetry collection Into Each Room We Enter Without Knowing (Southern Illinois University Press, 2017) was the recipient of the Crab Orchard Series in Poetry First Book Award, selected by Allison Joseph, and a finalist for the Lambda Literary Award for Gay Poetry and the Publishing Triangle's Thom Gunn Award.

Shanahan earned an AB in Comparative Literature from Princeton University; an AM in Comparative Literature and Literary Translation from Dartmouth College; and an MFA in Poetry from NYU's Graduate Creative Writing Program, where he studied with Sharon Olds and Yusef Komunyakaa, with whom he had first worked as an undergraduate at Princeton.

[4] Shanahan is currently an Assistant Professor of English and Creative Writing at Northwestern University, where he teaches in the undergraduate and Litowitz MFA+MA programs.

[7] His work has also been anthologized in African American Poetry: 250 Years of Struggle & Song (Library of America, 2020), Furious Flower: Seeding the Future of African American Poetry (Northwestern University Press, 2019), and American Journal: Fifty Poems for Our Time (Graywolf Press, 2018).

His translations of Italian-language poets Gëzim Hajdari and Donata Berra have been published in Circumference,[10] A Public Space, and RHINO Poetry.