To Mr. Gardner L. Boothe and the vestry of Christ Church, for permission to photograph the church.
To Mrs. Helen Lawrason Kirkpatrick, Miss Margaret Lawrason and Mrs. Edward Butler, for a wonderful day at the Lawrason plantation, Greenwood, in Louisiana, and the photographs of the Lawrason portraits.
To the Misses Carne, for the loan and use of valuable Alexandria documents.
To Miss Belle da Costa Green, of the Pierpont Morgan Library, for use of an important Martha Washington letter.
To Dr. St. George L. Sioussat, chief of the division of manuscripts of the Library of Congress.
To Mr. Allen L. Reese, for exciting finds among the Washington papers in that library.
To Mrs. Andrew Pickens, for notes on the Fowle family.
To Mr. Louis de Cazenove, for information on the Cazenove family.
To the late Mr. Cazenove Lee, for the story of General Robert E. Lee and the Edmund I. Lee house.
To Mr. W.B. McGroarty, for the letters and biographical information on Dr. Dick and permission to quote from his works.