Part I includes one brief diary and 72 letterpress books containing outgoing correspondence. The correspondence books have been grouped into the categories: Business, Civic Affairs, Private Letterbooks, and Miscellaneous. The Business Correspondence includes account books, Dairyman advertising books, general correspondence, and one volume of letters relating specifically to the Jefferson County Union. The Civic Affairs correspondence includes only that concerning Hoard's work for the St. Louis World's Fair. There are two sets of Private Letterbooks, one while Hoard was Governor and the other for the years following his term. Finally, there are three miscellaneous volumes. Within each category the volumes are in chronological order. Many of the letters are faded and nearly illegible.

The diary contains infrequent entries concerning both business appointments and personal matters for the months of February through July 1889.

Of the letterpress books pertaining to business, three are account books for advertising in both the Jefferson County Union and Hoard's Dairyman, covering the period from November 1889 to September 1895. The twenty-two Dairyman advertising books, January 1889 to April 1894, primarily contain letters seeking clients for advertising space in Hoard's Dairyman. There are also eleven volumes of general business correspondence, June 1880 to December 1899, pertaining mainly to Hoard's publishing career. And one volume, labelled the Jefferson County Union, consists of letters soliciting subscriptions and advertisers, and dates from January 1893 to March 1894.

There are two volumes of Hoard's correspondence as president of the Wisconsin exhibit at the St. Louis World's Fair, 1903 to 1906. These volumes are listed under Civic Affairs in the contents list.

Hoard's five Private Letterbooks as the Governor of Wisconsin from 1889 through 1890 consist of both Executive and personal correspondence. This correspondence includes letters relating to speaking engagements, political appointments and other political matters, as well as correspondence concerned with his dairying and journalistic interests and personal affairs.

The twenty-five volumes of Hoard's Private Letterbooks from the period following his governorship, 1890-1909, are also concerned with his interests in dairying and journalism and included non-business correspondence, some with family and friends.

There are three miscellaneous volumes, not identified by Hoard, which do not fit chronologically into the above categories. The first volume contains correspondence concerning Hoard's campaign for governor in 1888. The second is private and business correspondence of Hoard's eldest son, Halbert L. Hoard, from March 1891 to July 1908. The third incorporates business and personal correspondence written by Hoard from Trenton, New Jersey, Washington, D.C., and Espanore Island, Michigan in January 1900, and January and July 1901.