The Horner Woolen Mills collection consists primarily of correspondence and financial records, the bulk of which date from 1903 to 1919.

The correspondence series, including general correspondence, letterpress copies of outgoing letters, and quotations and estimates, relate mostly to the mill's activities between 1907 and 1914. These partially document daily operations; the company's investment in real estate in Michigan and Oklahoma; and its interest, as contract creditors to the Southern Ballast Co., in the development of the Frisco Railroad at Mill Creek, Oklahoma. Another contractor, the Southern Surety Co., also represents the Horner Woolen Mills as stockholders.

The letterpress copies of outgoing letter are in chronological form, indexed by correspondent. The other correspondence series are arranged by subject or correspondent.

The bookkeeping records are incomplete and do not document one common time span. However, the information is presented in a manner consistent with modern accounting principles. The general ledger accounts show aggregate daily transactions, while the control accounts detail orders, sales, accounts receivable, and accounts payable by customer. The General Journal is the first book of entry, recording transactions chronologically by date.

Occasionally these records include unusual items. For example, an employee accident report is found on page 476 of the Order Copybook. The 1904 General Journal includes an inventory pricing list illustrating historical gross margin on a sales per pound basis; the 1952 General Journal contains supplementary financial worksheets. Insurance costs for the period 1909-1912 are itemized in the Inventory and Fixed Assets Journal. The monthly Sales Journals list no customer names.

Most blueprints are of a planned dormitory. There is no evidence in the collection that it was completed. Another blueprint, showing how a fire-proof window is constructed, was sent compliments of the manufacturer.