Buchanan is a city in Berrien County in the U.S. state of Michigan. The population was 4,456 at the 2010 census. The city is located at the southeast corner of Buchanan Township, about 5 miles (8 km) west of Niles.
According to the United States Census Bureau, the city has a total area of 2.57 square miles (6.66 km), of which 2.50 square miles (6.47 km) is land and 0.07 square miles (0.18 km) is water.
As of the census of 2010, there were 4,456 people, 1,901 households, and 1,136 families residing in the city. The population density was 1,782.4 inhabitants per square mile (688.2/km). There were 2,139 housing units at an average density of 855.6 per square mile (330.3/km). The racial makeup of the city was 86.6% White, 7.5% African American, 1.2% Native American, 0.3% Asian, 1.3% from other races, and 3.1% from two or more races. Hispanic or Latino of any race were 3.3% of the population.
There were 1,901 households of which 31.5% had children under the age of 18 living with them, 40.1% were married couples living together, 13.3% had a female householder with no husband present, 6.4% had a male householder with no wife present, and 40.2% were non-families. 34.8% of all households were made up of individuals and 14.9% had someone living alone who was 65 years of age or older. The average household size was 2.34 and the average family size was 3.01.
The median age in the city was 37.6 years. 24.6% of residents were under the age of 18; 9.3% were between the ages of 18 and 24; 26.3% were from 25 to 44; 25.6% were from 45 to 64; and 14.3% were 65 years of age or older. The gender makeup of the city was 48.1% male and 51.9% female.
As of the 2000 census, there were 4,681 people, 1,915 households, and 1,191 families in the city. The population density was 1,950.8 per square mile (753.1/km²). There were 2,098 housing units, for an average density of 874.3 per square mile (337.5/km²). The racial makeup of the city was 86.26% White, 10.23% African American, 1.92% multiracial, 0.60% other races, 0.51% Asian, and 0.47% Native American. Hispanics or Latinos of any race were 1.84% of the population.
There were 1,915 households out of which 30.9% had children under the age of 18 living with them, 44.5% were married couples living together, 13.3% had a female householder with no husband present, and 37.8% were non-families. 32.0% of all households were made up of individuals and 14.7% had someone living alone who was 65 years of age or older. The average household size was 2.41 and the average family size was 3.05.
The age structure of the population was diffuse, with 25.6% under the age of 18, 9.6% aged 18–24, 29.0% aged 25–44, 21.3% aged 45–64, and 14.5% 65 years of age or older. The median age was 35. Sex ratio was skewed toward females, with 87.5 males for every 100 females of all ages and 83.1 males for every 100 females 18 years or older.
Median income was $34,244 for a household and $43,860 for a family. Males had a median income of $32,950 versus $21,857 for females. Per capita income was $16,600. About 10.9% of families and 12.4% of the population were below the poverty line, including 14.7% of those younger than 18 and 10.7% of those older than 64.