[2] It was named to honor Lewis Cass, who was the 1848 Democratic nominee for president.

Religious persecution was responsible for bringing the first people of European ancestry to Cass County.

The Mormons, fleeing from Illinois, were the earliest settlers, and established a community at Indiantown in 1846.

At Indiantown, two of the three commissioners selected to locate a county seat were chosen.

Most of the people and businesses in Indian Town moved to Lewis shortly after it was laid out.

In 1856, a frame courthouse was built, and eight years later a small stone building was completed for the county treasurer's office.

In 1857, there was an attempt to relocate the county seat to Grove City; it was unsuccessful.

While it was being built, county offices were located in the Atlantic Motors building, where an attempted robbery of the treasurer's safe took place.

The final cost of the fourth courthouse was $130,000: $65,000 came from a county bond issue, $46,500 from insurance and the remaining was covered by a Public Works Administration federal grant.

It was dedicated on December 26, 1934, with the main speaker being the Governor of Iowa, Clyde L. Herring.

Despite Roosevelt winning by an even larger landslide nationally just four years later, he lost Cass County by more than 13%.