Grundy County was established on February 17, 1841. It was formed out of LaSalle County and named after U.S. Attorney GeneralFelix Grundy. The county was well known for its coal mines and attracted miners from Pennsylvania and other regions to work its deposits. The Diamond Mine Disaster occurred in Grundy County. The disaster took the lives of 68 men and boys who were trapped underground when water broke through into the mine after days of heavy rain and the pumps could not keep up with the rising water. 22 bodies were eventually recovered, the remaining 44 were left in the mine and the mine was sealed. Today a marker stands where they felt the majority of the bodies probably ended up.
Geography
According to the U.S. Census Bureau, the county has a total area of, of which is land and is water.
Climate and weather
In recent years, average temperatures in the county seat of Morris have ranged from a low of in January to a high of in July, although a record low of was recorded in January 1985 and a record high of was recorded in June 1988. Average monthly precipitation ranged from in February to in June.
As of the 2010 United States Census, there were 50,063 people, 18,546 households, and 13,431 families residing in the county. The population density was. There were 19,996 housing units at an average density of. The racial makeup of the county was 93.7% white, 1.2% black or African American, 0.7% Asian, 0.2% American Indian, 2.7% from other races, and 1.5% from two or more races. Those of Hispanic or Latino origin made up 8.2% of the population. In terms of ancestry, 28.3% were German, 23.0% were Irish, 12.7% were Italian, 9.4% were Polish, 8.6% were English, 7.1% were Norwegian, and 3.0% were American. Of the 18,546 households, 38.6% had children under the age of 18 living with them, 57.8% were married couplesliving together, 9.7% had a female householder with no husband present, 27.6% were non-families, and 22.5% of all households were made up of individuals. The average household size was 2.69 and the average family size was 3.16. The median age was 36.1 years. The median income for a household in the county was $64,297 and the median income for a family was $75,000. Males had a median income of $58,491 versus $36,592 for females. The per capita income for the county was $27,895. About 5.2% of families and 6.9% of the population were below the poverty line, including 8.0% of those under age 18 and 6.5% of those age 65 or over.
As part of Yankee rural Northern Illinois, Grundy County has generally been powerfully Republican, although it did support ProgressiveTheodore Roosevelt in 1912 when the Republican Party was mortally divided. Only one Democratic presidential candidate has ever won an absolute majority of Grundy County's vote – Franklin D. Roosevelt in 1932 – although in recent times the county has trended a little more Democratic and both Bill Clinton in 1996 and Barack Obama in 2008 won pluralities. However, in 2016 with economic concerns in the “Rust Belt”, Donald Trump did better than any Republican in this traditional GOP county since 1984, when Ronald Reagan came within 3,819 votes of clean-sweeping all fifty states.
