One of Clinton's best known organizations, the 20th Century Club, was first organized as a social group in 1897. It was named the 20th Century Club in 1902 when the group's focus expanded to include civic improvement projects. The club eventually affiliated with the General Federation of Women's Clubs. It provided women an opportunity to study and discuss current events as well as poetry and other literature.
One of the club's early projects was to take over the sponsorship of the community library. First started by Wisconsin Traveling Library in 1910, the library was operated under the direction of the 20th Century Club until the village assumed its operation in 1964.
The village government constructed a village hall in 1913, and the building is still used as a village hall, police station, and library. In 1914 a more modern high school was constructed, and the next year the village's sewerage system was completed - the first one constructed in Rock County.
Another change in the community during this era was the merger of the Methodist and Congregationalist Churches to form the First Presbyterian Church in 1919. A few years later another Methodist Church was established, and today there are seven churches in the village and one just four miles south of town. Also, in 1930 the Pella Lutheran Church was built, and in 1937 the Emmanuel Reformed Church organized. The latter group met in homes and in the Methodist Church building until it constructed its own church in 1950.
By the 1920's, the community had grown to 938 in population and a larger high school was needed. The new building constructed in 1924 now serves as the middle school. The school has had three additions to accomodate the district's increased enrollment.
During the 1930's the village, with the help of the Work Projects Administration (WPA) started to develop the park that had been purchased in 1929 on the north side of the village near the watertower. That park is known today as the Herb Reffue Village Park.
Two present-day Clinton businesses were established in the late 1920's and early 1930's. The DeLong Company, an agribusiness, was originaly founded by Frank Johnson and William DeLong in 1929. They had been in the grain and feed business in Darien and Avalon since 1913. Over the years the company expanded its grain and feed business to include storage of grain as well as the distribution of liquid fertilizer, weed control products, and food corn.
In 1937 the Clinton Consumer's Cooperative was organized in association with the Midland Cooperative and specialized in petroleum products. The company now is known as Badgerland Farm Center and is owned by Land of Lakes Cooperative.