Professor Bellion taught at Rutgers University and the College of William and Mary before joining the University of Delaware in 2004. As the Terra Foundation for American Art/Institut National d’Histoire de l’Art Visiting Professor in 2015, she taught at the Université de Paris 7 (Paris Diderot) and the École Normale Supérieure. An elected member and Advisory Council member of the American Antiquarian Society, she has been awarded grants and fellowships from the American Antiquarian Society, Center for Advanced Study in the Visual Arts (National Gallery of Art), Henry Luce Foundation, Library Company of Philadelphia, National Endowment for the Humanities, Omohundro Institute of Early American History and Culture, and Winterthur Museum. She has contributed to exhibitions at the National Gallery of Art, the Art Institute of Chicago, the Newberry Library, and the National Museum of Women in the Arts. Appointed as a trustee of the Biggs Museum of American Art by the governor of Delaware, she serves on the editorial boards for Bloomsbury, the University of Delaware Press, and the journals Early American Literature and Studies in Eighteenth-Century Culture.

Professor Bellion advises graduate students in American art history and teaches graduate seminars on methods and historiography, iconoclasm, sculpture, the transcultural arts of the colonial Americas, and the material cultures of 18th and 19th century New York and Philadelphia. Her undergraduate courses include surveys of American art history and 18th-century art as well as seminars on fakes and forgeries, illusionism, and the Peale family.