| Iowa Public Service | Waterloo | IA |
| Iowa Public Service | Eagle Grove | IA |
| Iowa River Light & Power | Eldora | IA |
| Iowa Sheet Metal Construction | Des Moines | IA |
| Iowa Soldiers Home | Marshalltown | IA |
| Iowa Southern Utilities | Kemper | IA |
| Iowa Southern Utilities | Burlington | IA |
| Iowa Southern Utilities | Centerville | IA |
| Iowa Southern Utilities | Eddyville | IA |
| Iowa State Capitol | Des Moines | IA |
| Iowa State College | Ames | IA |
| Iowa State Highway Commission | Ames | IA |
| Iowa State Hospital | Clarinda | IA |
| Iowa State Hospital | Independence | IA |
| Iowa State Penitentiary | Fort Madison | IA |
| Iowa State University | Ames | IA |
| Iowa Steel & Iron Works | Cedar Rapids | IA |
| Iowa Valley Sugar | Belmond | IA |
| Iowa Veterans Home | Marshalltown | IA |
| Iron Public Service | Salix | IA |
| Jacob E. Decker & Sons | Mason City | IA |
| Jaeger Manufacturing | Des Moines | IA |
| J. A. Neymeyer | Waterloo | IA |
| Jas. Stewart & Company | Ottumwa | IA |
| JC Building | Des Moines | IA |
| J.C. Hubinger Brothers | Keokuk | IA |
| JCPenney | Des Moines | IA |
| JCPenney | Sioux City | IA |
| J. Deere Tractor | Dubuque | IA |
| J.E. Decker & Sons | Mason City | IA |
| Jefferson County Health Center | Fairfield | IA |
| Jefferson Electric Company | Jefferson | IA |
| Jeld Wen | Dubuque | IA |
| Jennie Edmundson Hospital | Council Bluffs | IA |
| J. F. Pritchard & Company | Creston | IA |
| J.H. Hertsche | Hamburg | IA |
| J. I. Case | Bettendorf | IA |
| J. Morrell & Company | Ottumwa | IA |
| John Deere | Waterloo | IA |
| John Deere | Des Moines | IA |
| John Deere | Ankeny | IA |
| John Deere | Dubuque | IA |
| John Morrell & Company | Ottumwa | IA |
| John Neff Cedar Falls Paper | Cedar Falls | IA |
| Johns Manville | Wilton | IA |
| Johnson Gas Appliance | Cedar Rapids | IA |
| Johnson Machine Works | Chariton | IA |
| Johnson School | Davenport | IA |
| Johnston Tombigbee Furniture Manufacturing | Chariton | IA |
| Jones As Terminal Sts | Dubuque | IA |
