Delmar is a city in Clinton County, Iowa, United States. The population was 542 at the time of the 2020 census. History Delmar was platted in 1871, shortly after the railroad was built through the site. The name Delmar is said to be a combination of the names of six ladies on the first train to arrive into the station. Le Mars, Iowa was similarly so named. Geography Delmar is located at (42.001744, -90.607683). According to the United States Census Bureau, the city has a total area of , all land. Demographics 2010 census As of the census of 2010, there were 525 people, 213 households, and 145 families living in the city. The population density was . There were 227 housing units at an average density of . The racial makeup of the city was 97.0% White, 1.5% African American, 0.2% Native American, 0.2% Asian, and 1.1% from two or more races. Hispanic or Latino of any race were 1.5% of the population. There were 213 households, of which 33.8% had children under the age of 18 living with them, 54.0% were married couples living together, 8.0% had a female householder with no husband present, 6.1% had a male householder with no wife present, and 31.9% were non-families. 28.6% of all households were made up of individuals, and 12.6% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 3.03. The median age in the city was 38.5 years. 27% of residents were under the age of 18; 5.5% were between the ages of 18 and 24; 27.1% were from 25 to 44; 24.8% were from 45 to 64; and 15.6% were 65 years of age or older. The gender makeup of the city was 49.7% male and 50.3% female. 2000 census As of the census of 2000, there were 514 people, 195 households, and 141 families living in the city. The population density was . There were 210 housing units at an average density of . The racial makeup of the city was 99.42% White, 0.19% Native American, 0.19% Asian, and 0.19% from two or more races. Hispanic or Latino of any race were 0.58% of the population. There were 195 households, out of which 37.9% had children under the age of 18 living with them, 60.5% were married couples living together, 7.7% had