Suisun City grows roots around it's businesses Delaplane Kristin 1998 Suisun City had its roots in the 1850s. Credit for the discovery of the area dates back to 1850, when Curtis Wilson and Dr. John Baker happened to sail up the winding Suisun Slough and they recorded their finding. The environment was mainly tule land populated with mud hens and a herd of elk. 53783467322