The Horlbeck Cash and Estimate Book, 1839-1849, was kept by members of the Horlbeck building and architectural business. The first half of the book is a cash book listing expenses and income. Expenses were for laborers described as white and "negroe", lime, bricks and "negro cloth." The second half of the book lists projected costs, lists of supplies, descriptions and occasional floor plans and drawings for structures to be built, repaired, and remodeled. Buildings include a dwelling house for a "Colored Man" and an Engine House.
The Horlbeck Ledger, 1839-1847, is a bound volume by members of the Horlbeck building and architectural business. The book records work done for clients White and Black employees and specifies the type of repair, remodeling or construction jobs and supplies. Black employees are comprised of enslaved persons and freed men and women.