The collection consists of the personal and family papers of five members of the Blair and Lee families of Maryland, Washington, D.C., and Virginia -- Francis Preston Blair (1791-1876); his daughter, Elizabeth Blair Lee (1818-1906); her husband, Samuel Phillips Lee (1812-1897); their son, Blair Lee (1857-1944, Princeton Class of 1880); and his cousin, Andrew Alexander Blair (1848-1932) -- reflecting their various political, journalistic, naval, family, business, legal, and domestic interests. While the collection largely pertains to these five family members, their papers also contain a significant amount of correspondence, documents, and writings of other members of the Blair and Lee families. Among other topics, materials in this collection document the families' involvement in American politics spanning from the Jacksonian Era through World War I.

The Blair family papers consist primarily of papers of politician and journalist Francis Preston Blair (1791-1876), including writings and lectures, documents, family correspondence, articles and other materials related to his editorship of the Globe, estate records, and correspondence with prominent political figures, including many involved with the administration of Andrew Jackson. The papers of his daughter, Elizabeth Blair Lee, document the political and social lives of the Blair and Lee families, as well as her work with the Washington City Orphan Asylum. The papers of Blair's grandson, Andrew Alexander Blair, contain additional family correspondence and span his time at the United States Naval Academy prior to becoming a chemist.

The Lee family papers include the papers of Samuel Phillips Lee, which document his service in the United States Navy, including his involvement in the U.S. Coast Survey, as well as the management of the Silver Spring Farm, real estate ventures, and family and domestic life. The papers of his son, the lawyer and politician Blair Lee, relate to his life as a student, work as a lawyer and United States senator during World War I and the administration of Woodrow Wilson, service in various organizations, and personal and family life.