Capac was founded and platted by a group of men from Romeo headed by George R. Funstan and Judge DeWitt C. Walker in 1857. The judge named it after Huayna Capac, Sapa Inca of the Inca Empire. A nearby post office named "Pinery" was transferred to and renamed "Capac" in January 1858. The Grand Trunk Railroad opened a station in 1866. Capac incorporated as a village in 1873.
There were 620 households out of which 45.3% had children under the age of 18 living with them, 56.8% were married couples living together, 12.6% had a female householder with no husband present, and 25.0% were non-families. 21.5% of all households were made up of individuals and 11.1% had someone living alone who was 65 years of age or older. The average household size was 2.86 and the average family size was 3.33.
In the village the population was spread out with 33.2% under the age of 18, 9.7% from 18 to 24, 31.4% from 25 to 44, 16.7% from 45 to 64, and 8.9% who were 65 years of age or older. The median age was 30 years. For every 100 females there were 98.3 males. For every 100 females age 18 and over, there were 94.6 males.
The median income for a household in the village was $42,105, and the median income for a family was $47,727. Males had a median income of $40,739 versus $26,797 for females. The per capita income for the village was $16,297. About 8.1% of families and 10.9% of the population were below the poverty line, including 14.0% of those under age 18 and 3.9% of those age 65 or over.