The first prefabricated spatial structural system developed in the U.S. was the Unistrut system. This system was patented by Charles W. Attwood of the Attwood Development Company of Wayne, Michigan, which built the first building using the Unistrut System in 1944. Further development of the Unistrut system continued in 1949 when it was taken up by the Engineering Research Institute at the University of Michigan. Because of the small module sizes, the members were light and could be easily put together using simple tools. The Unistrut system was later renamed as “Moduspan.”