The City of Rockford, Illinois has had a long and rich industrial history. Over the past several decades the city has lost dozens of industrial buildings due to disinvestment and demolition. Rockford's greatest industrial growth into a variety of manufacturing sectors was from 1850 to 1930. 1930 was selected as the cut off due to the crushing impact the Great Depression had on halting's Rockford's industrial expansion for the next 8 years. In the events leading up to World War II Rockford's machine tool industry thrived due to its manufacture of armaments for the allies. The War effort accelerated Rockford's industrial growth and propelled it into the nation's second most important machine tool industrial center from the 1940s through the 1960s. The focus of this survey was to recognize, understand, and inventory the remaining structures that served as the foundation for Rockford's evolutionary and diversified industrial capacity that is still evidenced. A variety of factors fueled Rockford's industrial growth and expansion. The community served as a magnet that attracted innovative entrepreneurs that could bring their inventions to market; it had a transportation network for distribution of products; and it drew an inexhaustible skilled labor force that had a strong work ethic.