Catherine Milligan McLane, of Baltimore, Maryland, was born 25 March 1850. She was the daughter of Louis McLane, Jr (1819-1905) and Sophia Hoffman. Her father served in the U.S. Navy and was Commander of Artillery of the California Battalion under the command of John C. Fremont. Fremont appointed him as one of the commissioners to sign the Articles of Capitulation between the United States and Mexican forces in California. Resigning from the Navy in 1850, McLane went into business with his father-in-law Samuel Hoffman, who with William W. Vanderbilt, had interests in the California Inland Steam Navigation Company. Afterwards he worked with Wells Fargo in 1855, eventually becoming its President, as well as the President of the Nevada Bank of San Francisco. He returned to Baltimore about 1868 becoming the President of the Mercantile Trust Company, eventually dying at that city in 1905. In the rear of this diary, dated 1906-1907, there are about ten pages concerning her father's estate and some dispute about it.

Catherine was known to have made several overland trips to California with her father in 1867-1868. She also made several trips by steamer to Europe with her two sisters, Elizabeth and Sophia, who, like Catherine, never married. Catherine first filed for a passport application in 1873. Catherine died on April 12, 1927.