Mary Pickersgill and the Star-Spangled Banner tells the story of how a young widow in the summer of 1813 made two large flags for Fort McHenry in Baltimore. The young United States was at war with Great Britain, and Fort McHenry prepared for an attack from the British. All was ready at the fort except for a proper set of flags. George Armistead, commander at Fort McHenry, needed the hand sewn flags in a hurry giving Mary Pickersgill just six weeks to produce them. This book will explain how Mary Pickersgill learned to make flags, where she obtained the four hundred yards of fabric, woven only in England, to make the flag, how she organized a small work force of young women, including a free African-American indentured servant, to sew the flags and where she found a workplace to make such large flags. Surprisingly, Mary Pickersgill did not consider sewing the Star-Spangled Banner the greatest accomplishment of her life. Under her leadership, a Baltimore charitable organization helped poor widows find work to support their families. The organization raised the funds to build the Home for Aged Widows that opened with great publicity and fanfare six years before Mary Pickersgill died. The Pickersgill Retirement Home in Towson has its roots in Mary Pickersgill's crowning achievement of her lifetime.

The stirring history of Mary Pickersgill's family is included in the book and helps explain Mary Pickersgill's drive and determination to produce the flags for Fort McHenry when the city of Baltimore was under imminent attack. The book also describes how the Star-Spangled Banner became the most important object in the Smithsonian's vast collection. In addition, the book recounts the history of the Star-Spangled Banner Flag House Association that preserved the little house on the corner of Pratt and Albemarle Streets as a museum to honor Mary Pickersgill's legacy.