It was named after the Polish general Tadeusz Kościuszko who served in the American Revolutionary War and then returned to Poland.

[4] The Indiana State Legislature passed an omnibus county bill[5] on February 7, 1835, that authorized the creation of thirteen counties[6] in northeast Indiana, including Kosciusko.

Kosciusko County terrain consists of low rolling hills dotted with bodies of water and drainages, with all available area devoted to agriculture or urban development.

[7] Its highest point (1025'/312 meters ASL) is a hill NE of Dewart Lake.

Representatives, elected to four-year terms from county districts, are responsible for setting salaries, the annual budget, and special spending.

The commissioners execute the acts legislated by the council, collect revenue, and manage the county government.

The judge on each court is elected to a term of six years and must be a member of the Indiana bar.

Woodrow Wilson in 1912 and Franklin D. Roosevelt in 1932 are the only two Democratic Party candidates to win the county from 1888 to the present day.

For example, Roosevelt actually lost the county by eight percentage points in 1936 even as he went on to carry 46 states.

As of the 2010 United States Census, there were 77,358 people, 29,197 households, and 20,740 families in the county.