It was the area's abundant natural resources that attracted its first recorded settlers, members of the Potawatomi and Winnebago tribes. Deep woodlands and clear lakes provided the tribes with wild game, fish and the raw materials to build their tools and homes, and it was they who named the area "Coo-No- Mo-Wauk," or "Where the Waters Meet."
The first white settlers were Charles Sheldon and Phil Brewer, who, in 1837, built log cabins in the area. The pair were soon followed by other settlers lured by stories of the area's beauty and abundant resources. Early settler John S. Rockwell was responsible for establishing a great deal of the town's foundation. The young entrepreneur built a grist mill and established the town's first store, hotel, fire department, and library. The "Father of Oconomowoc," as he came to be known, also donated land for the community's churches, and started Bord du Lac, a women's seminary.
Oconomowoc was incorporated as a city in 1865, and by 1875 its population had grown to almost 3,000. Following the arrival of the railroad, Oconomowoc became a favorite summer retreat for tourists and wealthy resorters from Chicago, Milwaukee, St. Louis and other Midwestern cities. Some of the nation's wealthiest families built stately summer homes on the lakes, and by the 1880s Oconomowoc featured six luxury resorts. From the 1870's until the Great Depression, Oconomowoc was known as the “Newport of the West," and visits by Presidents Cleveland, Harrison, Grant, Taft, Coolidge, McKinley and Theodore Roosevelt earned Main Street the nickname “Avenue of the Presidents."
The area also attracted new businesses, such as the Carnation Company, now Outlook Foods, and the Oconomowoc Canning Company. Pabst Farms' became internationally known for its purebred livestock.
Oconomowoc's downtown has retained most of its historic 19th-century architecture, and numerous grand Victorian homes still grace area lakeshores. Many city homes and businesses are listed on the state and national Register of Historic Places and can be seen on a self-guided walking tour developed by the Oconomowoc Historical Society.
Oconomowoc area residents are proud of their history and keep it alive at a number of museums and historic sites. Holy Hill, located high in the rolling Kettle Moraine area northeast of Oconomowoc, features a historic Catholic church, monastery, and shrine. Honey Acres Museum & Nature Trail, in Ashippun, features exhibits on beekeeping and honey making. The museum is run by the Diehnelt family, which has been in the honey making business since 1852.
The Oconomowoc and Lake Country Museum, in Oconomowoc, recounts local history alive with a number of artifacts and exhibits. The museum’s “Streets of Old” Gallery” features displays of a turn of the century Victorian home, dentist office, barbershop, print shop, medical clinic, bank and John S. Rockwell’s general store. Ole Evinrude, an Oconomowoc resident who invented the boat motor in 1907, is the focus of an exhibit of early boat motors. Another Oconomowoc claim to fame is its setting for the 1939 premier showing of the movie “The Wizard of Oz.”
A highlight of any historic tour of the area is Old World Wisconsin. Located in the little town of Eagle, in the southeast corner of Waukesha County, it is the nation's largest outdoor museum dedicated to the history of rural life. Opened in 1976 by the Wisconsin Historical Society to commemorate the nation's bicentennial, the museum has grown to include more than 60 historic structures, and visitors are immersed in reenactments of 19th-century farm and village life.