Native Americans had once inhabited a large late historic village inPetersburg that contained "at least two periods of habitation dating to 1150 A.D. and 1400 A.D."[5]
In 1729, an unknown Frenchman sketched an area on his chart at what is nowBig Bone Lick State Park with a note that it was "where they found the bones of an elephant."[5] Another Frenchman,Charles le Moyne de Longueuil (1687–1755), would later be credited with being the first to investigate the Big Bone Lick area.[5]
In 1789, 10-year-oldJohn Tanner was captured by Ojibwe Indians across from the mouth of theGreat Miami River, while his Baptist minister father, brother, and their slaves were planting corn.
Boone County was created in 1798, and named afterDaniel Boone.
On January 28, 1856, Robert and a pregnantMargaret "Peggy" Garner, together with family members, escaped and fled to Cincinnati, Ohio, along with several other slave families. Seventeen people were reported to have been in their party. In the coldest winter in 60 years, the Ohio River had frozen. The group crossed the ice just west of Covington, Kentucky at daybreak, and escaped to Cincinnati, then divided to avoid detection. They set out for Joseph Kite's house in Cincinnati.[6]
Margaret Garner would become famous for slitting her own daughter's throat (Mary) to prevent her from going back into slavery when Archibald K. Gaines and his posse, along with Federal Marshals, caught up to the fleeing slaves at Joseph Kite's house.[6]
Margaret Garner was first owned by, and may have been the daughter of, the plantation ownerJohn Pollard Gaines himself.[7] In December 1849, the plantation was given along with all the slaves to John P. Gaines' younger brother, Archibald K. Gaines.[7] The Gaines family lived on a farm called Maplewood in Boone County, Kentucky, just west of Richwood Presbyterian Church, of which Archibald K. Gaines was a member.[8] Three of Margaret Garner's children, including Mary, the daughter whose throat Margaret Garner slashed, were likely the children of Archibald K. Gaines, the only adult white male at Maplewood. The timing suggests they were each conceived after his wife had become pregnant and was unavailable to him.[9]
According to theUnited States Census Bureau, the county has a total area of 256 square miles (660 km2), of which 246 square miles (640 km2) is land and 10 square miles (26 km2) (3.9%) is water.[10] Its location along theOhio River was key to its early development, as the river was the major transportation route.
As of the2020 census, the county had a population of 135,968. The median age was 37.5 years. 26.4% of residents were under the age of 18 and 13.9% of residents were 65 years of age or older. For every 100 females there were 98.1 males, and for every 100 females age 18 and over there were 95.9 males age 18 and over.[16][17]
88.5% of residents lived in urban areas, while 11.5% lived in rural areas.[18]
There were 49,180 households in the county, of which 36.9% had children under the age of 18 living with them and 22.3% had a female householder with no spouse or partner present. About 22.1% of all households were made up of individuals and 8.7% had someone living alone who was 65 years of age or older.[16]
There were 51,468 housing units, of which 4.4% were vacant. Among occupied housing units, 73.0% were owner-occupied and 27.0% were renter-occupied. The homeowner vacancy rate was 1.0% and the rental vacancy rate was 5.6%.[16]
As of thecensus[19] of 2000, there were 85,991 people, 31,258 households, and 23,443 families residing in the county. Thepopulation density was 349 per square mile (135/km2). There were 33,351 housing units at an average density of 135 per square mile (52/km2). The racial makeup of the county was 85.3%White, 5%Black orAfrican American, 0.23%Native American, 2.6%Asian, 0.2%Pacific Islander, 0.75% fromother races, and 2.3% from two or more races. 4.98% of the population wereHispanic orLatino of any race.
There were 31,258 households, out of which 39.80% had children under the age of 18 living with them, 61.60% weremarried couples living together, 9.80% had a female householder with no husband present, and 25.00% were non-families. 20.20% of all households were made up of individuals, and 6.20% had someone living alone who was 65 years of age or older. The average household size was 2.73 and the average family size was 3.17.
In the county, the population was spread out, with 28.70% under the age of 18, 8.50% from 18 to 24, 33.50% from 25 to 44, 21.30% from 45 to 64, and 8.10% who were 65 years of age or older. The median age was 33 years. For every 100 females there were 97.70 males. For every 100 females age 18 and over, there were 94.70 males.
The median income for a household in the county was $53,593, and the median income for a family was $61,114. Males had a median income of $42,105 versus $27,414 for females. Theper capita income for the county was $23,535. About 4.40% of families and 5.60% of the population were below thepoverty line, including 6.40% of those under age 18 and 7.70% of those age 65 or over.
Boone County is a solidly Republican county in presidential elections; the last time it voted Democratic was in 1964, whenLyndon B. Johnson won ina national landslide. In 1976, however, the county gave exactly the same number of votes to DemocratJimmy Carter and RepublicanGerald Ford.
Before 2001, Boone County had a county police department providing general-service law enforcement to theunincorporated areas of the county. The police department was merged with the county sheriff's department in 2001, and the sheriff's department now serves that role.[21] As of 2025, the Boone County Sheriff's Office is the largest full service Sheriff's Office in the Commonwealth of Kentucky, providing 24-hour law enforcement, as well as a myriad of other services. Sheriff Michael A. Helmig retired in April 2025, after having served in that role since 1997. Long-time Chief Deputy, Les Hill, was appointed as his successor.[22]
The Boone County Jail is a short-term incarceration facility serving all law enforcement agencies in Boone County, including theKentucky State Police, the Florence Police Department, the Boone County Sheriff's Office, and the Cincinnati/Northern Kentucky International Airport Police Department. The Boone County Jail system consists of the main jail and a workcamp facility. The Main Jail has the capacity of housing 424 maximum, medium, and minimum security inmates. The workcamp houses 76 minimum security inmates. As of 2022[update] the Jailer, who in Kentucky is elected separately from the Sheriff, is Jason Maydak.[23]
^Steven Weisenburger, "A Historical Margaret Garner"Archived May 20, 2011, at theWayback Machine, Michigan Opera Theatre. Retrieved April 20, 2009. "Bertram Wyatt-Brown reminds us, Southern men commonly referred to their pregnant wives' last trimester or so when they were sexually unavailable as "the gander months" because it was supposedly natural, and to some extent informally countenanced, for them to seek intimate "comfort" with unmarried women or with enslaved women, if they owned any."
