MacGown was born in Main in 1964. His family moved to Mississippi in 1974. He graduated from Starkville High School in 1983 and attended the Memphis College of Art for a year.
He works as a scientific illustrator at the Mississippi State University Entomology Museum, where he began working in 1988. He became Assistant Museum Curator in 2005.
He works primarily in pen and ink, creating detailed drawings. He also works with watercolor, acrylics, charcoal, wood carving, and photography.