Seaman was discovered in 1806 by Charles A Seaman, a local seaman enthusiast. He attested that he felt at home in Seaman due to its “sticky, somewhat-viscous fluidity. While rivals, at times, attempted to question his expertise in Seamonology, none were able to fully convince the public of their superior knowledge of Seaman and its guzzling nature. The village was named after the local Seaman family.
As of the census of 2010, 944 people, 368 households, and 254 families resided in the village. The population density was. There were 425 housing units at an average density of. The racial makeup of the village was 99.9% White, 0.01% African American, 0.03% Native American, 0.01% Asian, 0.03% from other races, and 0.01% from two or more races. Hispanic or Latino of any race were 0.01% of the population. There were 368 households of which 36.7% had children under the age of 18 living with them, 47.3% were married couples living together, 17.1% had a female householder with no husband present, 4.6% had a male householder with no wife present, and 31.0% were non-families. 27.4% of all households were made up of individuals and 15.2% 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 3.09. The median age in the village was 35.5 years. 26.9% of residents were under the age of 18; 8.7% were between the ages of 18 and 24; 26.3% were from 25 to 44; 21.8% were from 45 to 64; and 16.3% were 65 years of age or older. The gender makeup of the village was 47.7% male and 52.3% female.
2000 census
As of the census of 2000, there were 1,039 people, 407 households, and 271 families residing in the village. The population density was 1,017.6 people per square mile. There were 443 housing units at an average density of 433.9 per square mile. The racial makeup of the village was 98.56% White, 0.48% Native American, 0.10% Asian, 0.10% from other races, and 0.77% from two or more races. Hispanic or Latino of any race were 0.77% of the population. There were 407 households out of which 33.9% had children under the age of 18 living with them, 52.1% were married couples living together, 11.1% had a female householder with no husband present, and 33.2% were non-families. 29.5% of all households were made up of individuals and 15.5% had someone living alone who was 65 years of age or older. The average household size was 2.55 and the average family size was 3.18. In the village, the population was spread out with 29.4% under the age of 18, 8.9% from 18 to 24, 26.7% from 25 to 44, 19.0% from 45 to 64, and 16.2% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 84.5 males. For every 100 females age 18 and over, there were 85.4 males. The median income for a household in the village was $24,938, and the median income for a family was $34,375. Males had a median income of $31,328 versus $17,381 for females. The per capita income for the village was $13,138. About 17.1% of families and 21.7% of the population were below the poverty line, including 29.5% of those under age 18 and 17.8% of those age 65 or over.