In 1919, C. Harold Wills left his lucrative position at the Ford Motor Company to pursue his own auto manufacturing dream. During his years at Ford, Wills made many contributions to Ford's success. It was Wills who promoted the development and use of vanadium steel, which was vital to the design of the Model T. He had assisted in the engineering of the Model T and designed the Ford script. When Wills left Ford he walked away with a profit sharing check of $1,592,128. Now he was ready to move out on his own.

Partnering with another former Ford employee, John R. Lee, they built an industrial community on the banks of the St. Clair River, in the town of Marysville Michigan. Wills added the "e" to the end of "Clair" because he said it looked "classier." The groundbreaking ceremony was held in November of 1919. It was not until two years later that they produced their first car.

Their first automobile was an 8-cylinder model propertied to be “10 years ahead of its time”. The car’s emblem was a Grey Goose. Wills had developed a strong admiration for geese, for years watching flocks of them fly overhead back and forth from their winter home in the south. In 1921 and 1922, the C.H. Wills & Company produced over 4,000 autos. They might have produced more except Wills was known for shutting down the assembly line whenever he thought of a new way to improve their product. His perfectionism drove colleagues away. By December of 1922, all of the company officers, including Lee, had resigned and the corporation shut down.

In 1923, with the help of a Boston bank, he reorganized and reopened as the Wills Sainte Claire Motor Company. In addition to his ever-changing V-8 he now produced a V-6. This was partly due to the heavy cost of producing the V-8 engine and partly due to complaints from his customers that the V-8 was too complicated for the average home mechanic to work on.

From 1923 through 1926 Wills sold over 5,000 cars. However, with his constant tinkering, it was never enough to make a profit. In 1927 the Wills Sainte Claire Motor Company produced its last car.

He went on to work as a metallurgy consultant for the Chrysler Corporation in the early 1930s. In 1935 Chrysler purchased the factory he had built. He died at the age of 62, on December 30, 1940.