In 1942 Hartigan began her artistic career as a draftsperson in Newark while studying art under Issac Lane Muse. After moving to New York in 1946, Hartigan became friendly with Avery, de Kooning, Kline, Pollock, Gottlieb, Motherwell, Baziotes, Rivers, Harold Rosenberg and the “New York School” poet Frank O’Hara. In 1950 her career was launched with her inclusion in the famous New Talent exhibition organized by Clement Greenberg and Meyer Schapiro at the Samuel Kootz Gallery.

Throughout the fifties Hartigan was featured in seven solo exhibitions at the Tibor de Nagy Gallery. She was also included in MoMA’s pivotal exhibition “Twelve Americans” of 1956 and in the influential international show “The New American Paintings” in 1958-59. During the mid-fifties she also appeared regularly in reviews and lengthy articles by the art magazines and newspapers including Life and Newsweek. Some of her masterpieces from this period include Persian Jacket, which impressed Alfred Barr and was acquired by MoMA. Her Grand Street Brides is now in the collection of the Whitney Museum

Her achievements are not limited to the historic moment of the “New York School.” In 1960 Hartigan moved to Baltimore. She became Director of the Hoffberger Graduate School of Painting, Maryland Institute College of Art in 1967. Her later works have continued to plumb art history, visual culture, biography, and, in her Great Queens and Empresses series, history. She has shown her boldness with stylistic experimentation, at times employing dripped and splattered paint along with powerful, gestural lines. She is the recipient of numerous awards and honors including a Life Time Achievement Award, Neuberger Museum, 2002, Governors Award, Baltimore, Maryland, 2006 and Honorary Degrees from Goucher College, Lafayette College, Maryland Institute College of Art, Moore College of Art, Towson State University and Dickinson College.

A member of the “New York School”during the 1950’s, she has made important contributions to the development of American painting throughout her long career. Her rich style, with its dynamic lines and sumptuous colors, fuses figuration and abstraction and often draws on elements of popular culture and art history.