beginning her research in the 1940s, breeskin authored two catalogue raisonnés on cassatt’s paintings, oils, and pastels and cassatt’s watercolors and drawings. she acted as curator of the cassatt retrospective exhibition at the national gallery of art in 1970 though she was simultaneously working on the sayn and johnson shows. several hours a week, breeskin devoted time to adding information to her catalogues and answering numerous questions from collectors from around the world.