Washtenaw County

administration
US state :	Michigan
Administrative headquarters :	Ann Arbor
Address of the administrative headquarters:	County Courthouse P.O. Box 8645 Ann Arbor, MI 48107-8645
Foundation :	December 31, 1826
Made up from:	Oakland County Wayne County
Area code :	+1 734
Demographics
Residents :	344,791 (2010)
Population density :	187.6 inhabitants / km ²
geography
Total area :	1871 km²
Water surface :	33 km²
map

Website : www.ewashtenaw.org

Washtenaw County is a county in the US state of Michigan . The county seat is Ann Arbor .

geography

The county is located in the southeast of the Lower Peninsula of Michigan, about 45 km to the south from Ohio and has an area of 1,871 square kilometers, of which 33 square kilometers are water. It borders on the following counties:

Ingham County	Livingston County	Oakland County
Jackson County		Wayne County
	Lenawee County	Monroe County

history

Washtenaw County was formed on December 31, 1826 from parts of Oakland County and Wayne County. It was named after the Indian expression O-wash-ten-nong .

78 structures and sites in the county are listed on the National Register of Historic Places (as of January 28, 2018).

Demographic data

growth of population
Census	Residents	± in%
1830	4042	-
1840	23,571	483.2%
1850	28,567	21.2%
1860	35,686	24.9%
1870	41,434	16.1%
1880	41,848	1 %
1890	42.210	0.9%
1900	47,761	13.2%
1910	44,714	-6.4%
1920	49,520	10.7%
1930	65,530	32.3%
1940	80,810	23.3%
1950	134,606	66.6%
1960	172,440	28.1%
1970	234.103	35.8%
1980	264,748	13.1%
1990	282.937	6.9%
2000	322,895	14.1%
2010	344,791	6.8%
Before 1900 1900–1990 2000 + 2010 Age pyramid of Washtenaw County (as of 2000)

As of the 2000 census , Washtenaw County had 322,895 people in 125,327 households and 73,692 families. The population density was 176 inhabitants per square kilometer. The racial the population was composed of 77.40 percent white, 12.29 percent African American, 0.36 percent Native American, 6.30 percent Asian, 0.04 percent from the Pacific island area and 1.04 percent from other ethnic groups Groups; 2.57 percent were descended from two or more races. 2.74 percent of the population were Hispanic or Latino of any of the above mentioned groups.

Of the 125,327 households, 29.2 percent had children under the age of 18 living with them. 46.4 percent were married couples living together, 9.3 percent were single mothers, and 41.2 percent were non-families. 29.5 percent were single households and 5.9 percent had people aged 65 or over. The average household size was 2.41 and the average family size was 3.02.

22.1 percent of the population were under 18 years old. 17.1 percent between 18 and 24 years of age, 32.1 percent between 25 and 44 years of age, 20.6 percent between 45 and 64 years of age, and 8.1 percent were 65 years of age or older. The median age was 31 years. For every 100 females there were 98.9 males. For every 100 women aged 18 and over there were 97.1 men.

The median income for a household in the county is $ 51,990 , and the median income for a family is $ 70,393. Males had a median income of $ 49,304 versus $ 33,598 for females. The per capita income was $ 27,173. 5.1 percent of families and 11.1 percent of the population are below the poverty line.