Scrapbook, 1898-1901, as an eligible bachelor in Washington. Mostly invitations and calling cards: Alexander Graham Bell, reception at the White House.

Scrapbook, 1901-1902, as an eligible bachelor in Washington. Mostly invitations and calling cards: three to events at the White House, several from various Roosevelts, one from Madame Bonaparte, one from Mrs. Alexander Graham Bell; one for the McKinley memorial service, and a program for McKinley's second inauguration.

Scrapbook of clippings and photos, 1906-1907. Mostly regarding the Mare Island Naval Yard and his appointment to canal post. Includes issue of the Vallejo Evening Chronicle covering the San Francisco fire, April 18, 1906; cyanotype of San Francisco after the fire.

Scrapbook of clippings and correspondence, 1914-1916. Includes a letter from servant Robert Isaacs. Letter from George Goethals releases Rousseau from service on Canal in May of 1916.

Guest book, 1909-1922, gilt-stamped "G.S.R." (Gladys Squiers Rousseau) on front board, mostly kept in Panama. Hundreds of signatures with home towns, including important diplomats and military figures. Most notable is young Franklin Delano Roosevelt, then a New York State senator, who visited in April 1912. George W. Goethals (July 13, 1911), Cornelius Vanderbilt III (April 18, 1912), Secretary of State Henry Stimson and First Lady Helen Taft (November 25, 1912), and Kermit Roosevelt (May 30, 1916).

Diary of trip to Costa Rica in May 1913 with extensive notes on trees.

Diary by Harry on a fact-finding mission to Mammoth Oil in Casper, WY, relating to the National Petroleum Reserve and Teapot Dome investigation, 1928.

Wallet of identification cards and train passes as well as naval ephemera and uniform items.

Books, pamphlets, printed maps, and a small quantity of photocopies and references, most relating to Panama and naval engineering.