Buchanan is a city in Berrien County in the U.S. state of Michigan. The population was 4,681 at the 2000 census. The city is located at the southeast corner of Buchanan Township, about 5 miles (8 km) west of Niles. Popularly known as "Redbud City" because of the many redbud trees that have historically lined city streets and the major approaches to the city, Buchanan has long been recognized as a Tree City USA by the National Arbor Day Foundation.
According to the United States Census Bureau, the city has a total area of 2.5 square miles (6.4 km²)
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.