William McIlvaine, primarily a watercolorist, received a master of arts degree from the University of Pennsylvania in 1832 and then traveled and studied in Europe for the next five years. Upon his return, he spent a number of years in his father’s business in Philadelphia before taking up art professionally about 1845. He traveled to the California gold fields and Mexico, gathering ideas for his paintings. In 1850 he published Sketches of Scenery and Notes of Personal Adventures in California and Mexico containing sixteen plates after his own views of the mines. A panorama based on his sketches was painted by Russell Smith and shown in Philadelphia in 1950 and Baltimore in 1851.

He exhibited at the Pennsylvania Academy of the Fine Arts (1851-1855), the National Academy of Design (1857-1861), and the Brooklyn Art Association (1864).

McIlvaine lived in Philadelphia until about 1856 when he moved to New York City. During the Civil War, he served as a member of the New York 5th Regiment of Volunteers.