As the resources of the small country town were depleted, the amiable revelry began to turn ugly, and the residents of Zap asked the visitors to leave. Some of them complied, but others stayed behind, and the event became a full-fledged riot. The National Guard was called in and the crowd was dispersed.
According to the United States Census Bureau, the city has a total area of 1.0 square miles (2.7 km²), all of it land.
There were 101 households out of which 25.7% had children under the age of 18 living with them, 60.4% were married couples living together, 4.0% had a female householder with no husband present, and 31.7% were non-families. 29.7% of all households were made up of individuals and 14.9% had someone living alone who was 65 years of age or older. The average household size was 2.29 and the average family size was 2.78.
In the city the population was spread out with 21.6% under the age of 18, 5.2% from 18 to 24, 25.5% from 25 to 44, 33.3% from 45 to 64, and 14.3% who were 65 years of age or older. The median age was 44 years. For every 100 females there were 100.9 males. For every 100 females age 18 and over, there were 92.6 males.
The median income for a household in the city was $30,536, and the median income for a family was $34,063. Males had a median income of $30,625 versus $18,125 for females. The per capita income for the city was $16,175. About 5.2% of families and 10.9% of the population were below the poverty line, including 18.6% of those under the age of eighteen and 18.2% of those sixty five or over.