Very little is known of Colonel Daniel S. Lamson, except that he was a devoutly religious Catholic who was a philanthropist and an amateur historian. He was born around 1827, probably in Weston, Massachusetts, attended Catholic schools in France and graduated from Harvard Law School. He seems to have lived on inherited wealth, because he never practiced law. Evidence in the collection shows that he did some work in business, as he was elected Vice President of Union Institution of Savings in 1865 and there is a letter concerning a business deal in Mexico involving several U.S. Senators. He served in the Civil War for the Union in battles along the Potomac River, a clipping about which is in the collection. Lamson lived into the twentieth century, probably until at least 1913. Colonel Daniel S. Lamson did much work as an amateur historian, especially of Catholics in America. He published a book on the history of his home town of Weston, Massachusetts in 1913 and had at least one essay published ('The First Catholic Parochial School in Boston'). He was a member of the New England Catholic Historical Society and corresponded with other noted amateur historians, such as Richard H. Clarke. Lamson was a very religious man, with numerous friends and acquaintances in the clergy, including many Bishops, Archbishops and Jesuits. He had a strong connections with noted Jesuits at Boston College, including its first president, John Bapst, S.J. He was an early benefactor of the College, and in 1865 he gave a third of his personal library and a proprietor's share in the Athenaeum to Boston College. He also knew many Jesuits at Georgetown University, including Henry Shandelle, S.J. He also donated many books to Georgetown's library and even requested that these papers be given to GU before his death. The number of Catholic societies of which Lamson was a member, both in Boston and New York, is revealed in the collection of ephemera from the different organizations. The amount of donations he made to these societies and to houses of charity can be seen in the correspondence.