In 1903, Simonds formed Simonds and Company and was awarded the redesign and extension of Chicago's Lincoln Park with Bryan Lathrop and Francis T. Simmons. The plan was to double the parks 275 acres by extending it into Lake Michigan and later extended it north approximately 1,000 acres. To update the older sections, he incorporated winding pathways and facilities so as not to compromise the landscape. He relied on natural topography to create naturalistic "rooms" and scenic meadow vistas. He also designed golf courses, Belle Meade, city parks, town plans, universities including Iowa State and the University of Maryland, residences, and private estates around the country.