Platteville is the largest city in Grant County, Wisconsin, United States. The population was 11,836 at the 2020 census.

Platteville is located atop the greater Platte River valley in the southern Driftless Region of Wisconsin, an area known for its karst topography and rolling hills. It is home to the University of Wisconsin–Platteville. It is the principal city of the Platteville micropolitan statistical area, which has an estimated population of 51,938.

Platteville was settled by pioneers and early lead miners; along inlets and flat groves of The Rountree Branch and Little Platte River. Part of the Platte River shed; these rivers flow into the greater Upper Mississippi River system. More specifically located in the Driftless Region of Southwestern Wisconsin.

Due to its geographic location; areas of town are carved by ridges, narrow valleys, and steep hills. The influence of geography can also be seen in the irregularity of the streets in the community. As the town grew, roads were given odd routes, to avoid the steep ravines and mining shafts strewn about the locality.

Platteville was officially founded in 1829 by John H. Rountree, a southern businessman who had arrived in hopes of finding wealth during the areas lead rush. The town became a flourishing mining community in part due to its close proximity to Dubuque, Iowa, and Galena, Illinois. Both were thriving cities along the Mississippi River trade route that benefited from the rising demand for lead throughout the United States from the 1820s–1850s.

John H. Rountree and other wealthy southerners in the area, such as Wisconsin’s First Governor Henry Dodge; brought slaves with them during the lead rush. They also brought freed black laborers, with intentions for them to work the mines at a more affordable cost, often nothing. Although unpaid labor was illegal, it was practiced in the region until after the Civil War.

In 1850, a freed African-American man from Virginia, named Charles Shepard, settled a community known as Pleasant Ridge, Grant County, Wisconsin just west of Platteville. This served as a safe haven for many black people coming up the Mississippi River from Arkansas, Tennessee, Louisiana, etc. Some stayed and raised families but most continued on their way in hopes of finding success elsewhere.

By the 1860s lead ore production was decreasing. However, the mining of zinc ore quickly filled the void for prospective work. Platteville had become an established town, complete with schools, a private preparatory academy, newspaper, several churches, and a telegraph service as of November 1849.

During this time, both a teachers' college and a mining college were founded. The normal school was established on October 9, 1866 to train teachers for elementary school grades. The Wisconsin Mining Trade School opened in January 1908.

In 1959, these two colleges were merged to become Wisconsin State College and Institute of Technology. Its curriculum was developed to add graduate programs and departments, particularly in engineering. In 1971 it was renamed as University of Wisconsin–Platteville, to reflect its expanded programs in graduate study. Other additions included criminal justice and, in the early 21st century, UW Platteville is also considered to have the best criminal justice college in the Midwest.

From 1984 until 2001 the Chicago Bears football team held summer training camp on the campus of University of Wisconsin–Platteville. Their program resulted in a substantial infusion of money into the local economy each summer. The town felt the decline after the Bears moved their training camp to Olivet Nazarene University in Illinois.

In 2004, U.S. Highway 151 was upgraded to a limited-access highway; it bypassed the city south of Platteville. Prior to the upgrade, the highway exits were closer to Platteville. The city made changes to adjust to the new southern US 151 bypass, and it has influenced subsequent development. A new hospital was built just north of US 151 and next to its off ramps. A Walmart Supercenter and a Menards have opened near the northern end of the US 151 bypass.

• 
  Former Carnegie library building
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  Ullrich Hall, part of the University of Wisconsin-Platteville

Platteville is located at 42°44′13″N 90°28′39″W / 42.73707°N 90.477501°W / 42.73707; -90.477501 (42.73707, −90.477501). It is in the Hollow Region, as named by early southern miners, in the rolling hills of southwestern Wisconsin.

According to the United States Census Bureau, the city has a total area of 6.18 square miles (16.01 km), all of it land.

Platteville is serviced by Wisconsin State Highways 80 and 81, as well as U.S. Highway 151.

The minerals in the area consist of galena, a sulfide of lead (lead 86.6, sulfur 13.4). Sphalerite or zinc sulfide is also, common in the region. Zinc and lead mining were in heavy production through the 1820s–1920s.

Historical population

Census	Pop.	Note	%±
1870	2,537		—
1880	2,687		5.9%
1890	2,740		2.0%
1900	3,340		21.9%
1910	4,452		33.3%
1920	4,353		−2.2%
1930	4,047		−7.0%
1940	4,762		17.7%
1950	5,751		20.8%
1960	6,957		21.0%
1970	9,599		38.0%
1980	9,580		−0.2%
1990	9,708		1.3%
2000	9,989		2.9%
2010	11,224		12.4%
2020	11,836		5.5%
2021 (est.)	11,764		−0.6%
U.S. Decennial Census

As of the census of 2020, the population was 11,836. The population density was 1,915.8 inhabitants per square mile (739.7/km). There were 4,423 housing units at an average density of 715.9 per square mile (276.4/km). The racial makeup of the city was 90.9% White, 2.2% Black or African American, 2.0% Asian, 0.2% Native American, 1.2% from other races, and 3.4% from two or more races. Ethnically, the population was 3.1% Hispanic or Latino of any race.

The 2020 census population of the city included 2,858 people in student housing.

According to the American Community Survey estimates for 2016-2020, the median income for a household in the city was $42,626, and the median income for a family was $75,625. Male full-time workers had a median income of $43,303 versus $31,915 for female workers. The per capita income for the city was $20,781. About 7.5% of families and 30.0% of the population were below the poverty line, including 16.4% of those under age 18 and 13.8% of those age 65 or over. Of the population age 25 and over, 95.1% were high school graduates or higher and 41.8% had a bachelor's degree or higher.

As of the census of 2010, there were 11,224 people, 3,644 households, and 1,598 families residing in the city. The population density was 2,059.4 inhabitants per square mile (795.1/km). There were 3,840 housing units at an average density of 704.6 per square mile (272.0/km). The racial makeup of the city was 94.7% White, 2.1% African American, 0.2% Native American, 1.7% Asian, 0.3% from other races, and 1.0% from two or more races. Hispanic or Latino of any race were 1.6% of the population.

There were 3,644 households, of which 18.2% had children under the age of 18 living with them, 32.7% were married couples living together, 7.8% had a female householder with no husband present, 3.3% had a male householder with no wife present, and 56.1% were non-families. 31.4% of all households were made up of individuals, and 11.6% had someone living alone who was 65 years of age or older. The average household size was 2.32 and the average family size was 2.80.

The median age in the city was 22.4 years. 11.3% of residents were under the age of 18; 49.4% were between the ages of 18 and 24; 14.3% were from 25 to 44; 14.3% were from 45 to 64; and 10.7% were 65 years of age or older. The gender makeup of the city was 56.3% male and 43.7% female.

As of the census of 2000, there were 9,989 people, 3,312 households, and 1,692 families residing in the city. The population density was 2,376.4 people per square mile (918.3/km). There were 3,482 housing units at an average density of 828.4 per square mile (320.1/km). The racial makeup of the city was 96.15% White, 1.12% Black or African American, 0.27% Native American, 1.40% Asian, 0.04% Pacific Islander, 0.27% from other races, and 0.75% from two or more races. 0.88% of the population were Hispanic or Latino of any race. There were 3,312 households, out of which 22.2% had children under the age of 18 living with them, 40.0% were married couples living together, 8.0% had a female householder with no husband present, and 48.9% were non-families. 32.2% of all households were made up of individuals, and 13.0% had someone living alone who was 65 years of age or older. The average household size was 2.31 and the average family size was 2.86.

In the city, the population was spread out, with 14.4% under the age of 18, 41.3% from 18 to 24, 17.5% from 25 to 44, 14.4% from 45 to 64, and 12.3% who were 65 years of age or older. The median age was 23 years. For every 100 females, there were 119.3 males. For every 100 females age 18 and over, there were 120.6 males.

The median income for a household in the city was $35,742, and the median income for a family was $50,583. Males had a median income of $31,424 versus $21,896 for females. The per capita income for the city was $15,858. About 4.6% of families and 19.4% of the population were below the poverty line, including 12.2% of those under age 18 and 8.3% of those age 65 or over.

The Mining and Rollo Jamison Museums examines Platteville's mining history.

Built in 1837 by Reverend Samuel Mitchell, the Stone Cottage still contains many of the original furnishings. The home was a home of the Major John Rountree, one of Platteville's founders. The walls are two feet thick and made of dolomite Galena limestone.

The Platte Mound M is the letter "M" written using whitewashed stones on Platte Mound about four miles east of downtown Platteville. It is the largest hillside letter "M" in the world. The letter is 241 feet (73 m) high, 214 feet (65 m) wide, with legs 25 feet (7.6 m) wide.