In 1894, as a result of a special election, the county seat was moved from Helena to Karnes City.

Ten years earlier, Colonel William G. Butler (1831–1912) had blamed Helena and its corrupt mayor for the death of his son, Emmett, who was killed on December 26, 1884, by a stray bullet from a bar fight.

Butler, a wealthy rancher, retaliated by arranging for the San Antonio and Aransas Pass Railway, which started construction in 1885, to bypass Helena.

In 1890, a group of businessmen purchased land on the rail line, 7 miles (11 km) southwest of Helena, with the specific intent of building a new town to serve as the county seat.

Karnes City continued to grow, while Helena faded into a ghost town.

The story was fictionalized in the 1969 episode "The Oldest Law" of the television series Death Valley Days.

The climate in this area is characterized by hot, humid summers and generally mild to cool winters.