St. Thomas was laid out in 1881. The city was named after St. Thomas, Ontario. A U.S. post office has been in operation at St. Thomas since 1881 and is open weekdays. The St. Thomas Public School was established in 1882. St. Thomas Elementary School and St. Thomas High School offer classes for pre-kindergarten through 12th grade. An extended school program is available after school hours. The St. Thomas Cafe is open for breakfast and lunch Monday through Saturday from 7 a.m. to 2.30 p.m.
Geography
St. Thomas is located at . According to the United States Census Bureau, the city has a total area of, all of it land.
As of the census of 2010, there were 331 people, 150 households, and 107 families residing in the city. The population density was. There were 182 housing units at an average density of. The racial makeup of the city was 94.6% White, 0.6% Native American, 4.5% from other races, and 0.3% from two or more races. Hispanic or Latino of any race were 19.6% of the population. There were 150 households of which 27.3% had children under the age of 18 living with them, 53.3% were married couplesliving together, 9.3% had a female householder with no husband present, 8.7% had a male householder with no wife present, and 28.7% were non-families. 27.3% of all households were made up of individuals and 11.3% had someone living alone who was 65 years of age or older. The average household size was 2.21 and the average family size was 2.63. The median age in the city was 46.1 years. 19.6% of residents were under the age of 18; 5.7% were between the ages of 18 and 24; 21.7% were from 25 to 44; 35.2% were from 45 to 64; and 17.8% were 65 years of age or older. The gender makeup of the city was 52.6% male and 47.4% female.
2000 census
As of the census of 2000, there were 447 people, 174 households, and 123 families residing in the city. The population density was 421.7 people per square mile. There were 201 housing units at an average density of 189.6 per square mile. The racial makeup of the city was 94.18% White, 4.25% from other races, and 1.57% from two or more races. Hispanic or Latino of any race were 19.02% of the population. There were 174 households out of which 32.2% had children under the age of 18 living with them, 56.3% were married couples living together, 8.0% had a female householder with no husband present, and 29.3% were non-families. 26.4% 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 2.57 and the average family size was 3.13. In the city, the population was spread out with 29.8% under the age of 18, 4.0% from 18 to 24, 26.8% from 25 to 44, 23.5% from 45 to 64, and 15.9% who were 65 years of age or older. The median age was 37 years. For every 100 females, there were 103.2 males. For every 100 females age 18 and over, there were 100.0 males. The median income for a household in the city was $31,094, and the median income for a family was $44,375. Males had a median income of $26,023 versus $22,083 for females. The per capita income for the city was $18,222. About 14.3% of families and 17.3% of the population were below the poverty line, including 23.0% of those under age 18 and 16.4% of those age 65 or over.
