Wheelock began his career in museums as a David E. Finley Fellow at the
National Gallery of Art in 1973 and later was also named Research Curator, under director
J. Carter Brown. He also commenced teaching at the
University of Maryland, where he has held the post of Professor of Art History. Wheelock was appointed Curator of Dutch and Flemish Painting at the National Gallery of Art two years later, which eventually led to his appointment as Curator of Northern Baroque Paintings. He has lectured widely on
Dutch and
Flemish art and has authored several publications on the subjects, particularly concerning
Johannes Vermeer, church painters, and those interested in optics. He curated one of the first exhibitions on the Dutch painter
Judith Leyster, titled 'Judith Leyster: The First Woman to Become a Master Painter', which was on display at the National Gallery of Art from June 21-November 29, 2009. In 2018, he received the
honorary degree of
Doctor of Arts from
Dickinson University. ==Awards and honors==