This document discusses the history of case construction bookbinding in the United States between 1820-1850. During this period, case construction emerged as the dominant method of book manufacturing over previous techniques like laced construction. Key developments included the introduction of trimmed edges, whole cloth covers, and metal edged pressing boards. Case binding allowed for faster production speeds and facilitated cloth covering and finishing. By the late 19th century, case construction was the standard industrial process in American bookbinding.