Originally named Nation, the present name recalls an episode when water had to be carried to the town site for the railroad. A post office called Nation was established in 1880, and the name was changed that same year to Bridgewater.
As of the census of 2010, there were 492 people, 204 households, and 133 families residing in the city. The population density was. There were 254 housing units at an average density of. The racial makeup of the city was 98.4% White, 0.4% Native American, 0.6% Asian, 0.4% from other races, and 0.2% from two or more races. Hispanic or Latino of any race were 2.0% of the population. There were 204 households, of which 28.9% had children under the age of 18 living with them, 48.5% were married couplesliving together, 11.8% had a female householder with no husband present, 4.9% had a male householder with no wife present, and 34.8% were non-families. 33.3% of all households were made up of individuals, and 21.1% had someone living alone who was 65 years of age or older. The average household size was 2.24 and the average family size was 2.77. The median age in the city was 48.4 years. 23.8% of residents were under the age of 18; 2.6% were between the ages of 18 and 24; 19% were from 25 to 44; 25.6% were from 45 to 64; and 29.1% were 65 years of age or older. The gender makeup of the city was 45.3% male and 54.7% female.
2000 census
As of the census of 2000, there were 607 people, 245 households, and 147 families residing in the city. The population density was 541.4 people per square mile. There were 266 housing units at an average density of 237.3 per square mile. The racial makeup of the city was 98.35% White, 0.33% Native American, 0.33% Asian, 0.33% from other races, and 0.66% from two or more races. Hispanic or Latino of any race were 1.81% of the population. There were 245 households, out of which 27.3% had children under the age of 18 living with them, 50.6% were married couples living together, 6.5% had a female householder with no husband present, and 39.6% were non-families. 35.5% of all households were made up of individuals, and 25.3% had someone living alone who was 65 years of age or older. The average household size was 2.31 and the average family size was 3.07. In the city, the population was spread out, with 25.4% under the age of 18, 4.9% from 18 to 24, 21.7% from 25 to 44, 19.6% from 45 to 64, and 28.3% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 87.9 males. For every 100 females age 18 and over, there were 82.7 males. The median income for a household in the city was $31,765, and the median income for a family was $39,375. Males had a median income of $28,611 versus $21,458 for females. The per capita income for the city was $15,855. About 5.5% of families and 9.5% of the population were below the poverty line, including 13.0% of those under age 18 and 10.4% of those age 65 or over.
Climate
Humid continental climate is a climatic region typified by large seasonal temperature differences, with warm to hot summers and cold winters. Precipitation is relatively well distributed year-round in many areas with this climate. The Köppen Climate Classification subtype for this climate is "Dfa".
