The population peaked at 17,691 in 1940, but as of the 2000 census had dropped to 9,175 and was still declining at mid-decade according to census bureau estimates. Two adjoining townships, home to approximately 9,000 people, make the population of Greater Bradford about 18,000. Famous Bradfordians include opera singer Marilyn Horne and Hall of Fame pitcher Rube Waddell. A famous Perpetual Motion machine Hoax was created in Bradford in 1897 by J M Aldrich; it was exposed in the July 1 1899 issue of the Scientific American magazine, leading to a four month prison sentence in the county jail.
As of the census of 2000, there were 9,175 people, 3,922 households, and 2,247 families residing in the city. The population density was 2,659.7 people per square mile (1,026.8/km²). There were 4,371 housing units at an average density of 1,267.1/sq mi (489.2/km²). The racial makeup of the city was 97.74% White, 0.49% African American, 0.31% Native American, 0.52% Asian, 0.03% Pacific Islander, 0.27% from other races, and 0.63% from two or more races. Hispanic or Latino of any race were 0.95% of the population.
There are 3,922 households, of which 29.4% have children under the age of 18, 36.9% have married couples living together and 14.8% have a female householder with no husband present. 42.7% of households are non-families, 36.3% are made up of individuals and 15.2% had someone living alone who was 65 years of age or older. The average household size was 2.27, and the average family size was 2.93.
25.4% of the population is under the age of 18, 9.4% from 18 to 24, 28.0% from 25 to 44, 20.0% from 45 to 64, and 17.1% 65 years of age or older. The median age is 36 years. For every 100 females there were 88.4 males. For every 100 females age 18 and over, there were 83.7 males.