65 years of age or older. The average household size was 3.38 and the average family size was 2.76. The city's age distribution consisted of 24.2% under the age of 18, 10.2% from 18 to 24, 25.2% from 25 to 44, 25.5% from 45 to 64, and 14.8% who were 65 years of age or older. The median age was 36.4 years. For every 100 females, there were 94.8 males. For every 100 females age 18 and over, there were 97.3 males. The median income for a household in the city was $52,609, and the median income for a family was $67,518. Males had a median income of $34,455 versus $27,676 for females. The per capita income for the city was $24,330. About 8.9% of families and 13.5% of the population were below the poverty line, including 18.7% of those under age 18 and 9.7% of those age 65 or over. Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos can be of any race. History Before the arrival of the mostly Anglo-Americans in the 19th century, this area was long occupied by the Illinois Confederation, a loose grouping of up to 12 to 15 Native American tribes. The main tribes were the Cahokia, Kaskaskia, Michigamea, Peoria, and Tamaroa. After trading, warfare and other encounters with French traders, who entered this area before the Anglo-Americans, their numbers declined. In large part that was due to the high mortality from new infectious diseases, which adversely affected Native Americans across the continent. The area that developed as Belvidere was first permanently settled by European Americans in 1835: Simon P. Doty and Daniel Hilton Whitney. They named this location next to the Kishwaukee River as "Elysian Fields" from Greek mythology. As many new residents could not pronounce or spell the proposed name, the city was eventually named after Belvidere, Virginia, the former home of Ebenezer Polk, a railroad lawyer and major financial founder in the city. Belvidere originally developed on the north side of the Kishwaukee River. In 1851 the Galena and Chicago Union Railroad was built south of the river, stimulating relocation of much of the business section to the south side of the river, for access to the railway transportion. Belvidere's downtown is now on the south side. Major industries developed along the river