Jackson County, Missouri

Jackson County is the principal county of Kansas City, Missouri, and the core of the bi-state Kansas City metropolitan area on the Missouri side of the state line. Organized in 1826 and named for Andrew Jackson, it holds the unusual distinction of dual county seats — Independence and Kansas City — and contains most of Kansas City, Missouri, along with Independence, Lee’s Summit, Blue Springs, Grandview, and Raytown. With a 2020 census population of 717,204, it is the second-most populous county in Missouri.¹²

Formation (1826) + naming

Jackson County was organized on December 15, 1826, and named for Andrew Jackson, then a U.S. senator from Tennessee who would be elected president in 1828 and take office in 1829.¹ Independence, at the time a small settlement near a spring, was designated the original county seat; its position on the western edge of organized U.S. territory made it a launching point for the Santa Fe, Oregon, and California trails during the era of westward expansion.¹

The dual county seats (Independence + Kansas City)

Jackson County is one of roughly three dozen U.S. counties to maintain more than one county seat: its seats are Independence and Kansas City.¹ Independence served as the sole seat in the county’s early decades, but after the Civil War and the arrival of the railroads, Kansas City grew rapidly and eventually eclipsed Independence in size and economic weight.¹ Both cities retain courthouse functions to this day, with county government splitting operations between the two — a structure that dates to the 19th century and persists in the modern county administration.

The Truman connection (presiding judge)

Before his national career, Harry S. Truman — the 33rd President of the United States — served in Jackson County government. Truman was elected Presiding Judge of the Jackson County Court in 1926, a position closer to a county executive or commissioner than a judicial office, and he held it for roughly eight years.¹³ As Presiding Judge he divided his time between the county’s two courthouses, in Independence and Kansas City, and is credited with improving county finances and overseeing a major public-works program that included a 230-mile road system, a county hospital, a new Kansas City courthouse, and a substantial remodeling of the Jackson County Courthouse in Independence.³ The Independence courthouse, with Truman’s preserved office, is today a National Park Service site within the Harry S. Truman National Historic Site network.³⁴

The modern county (population, municipalities, role in the metro)

The 2020 U.S. census recorded a Jackson County population of 717,204, making it the second-most populous county in Missouri after St. Louis County.¹² The county is the demographic and economic anchor of the Missouri side of the Kansas City metro. Most of Kansas City, Missouri lies within Jackson County (the city spills across the county line into Clay, Platte, and Cass counties as well), and the county also contains the major suburbs of Independence, Lee’s Summit, Blue Springs, Grandview, and Raytown, among other municipalities.¹ As the metro’s core Missouri-side county, it carries a large share of the region’s population, civic institutions, and downtown employment.

Significance to Kansas City

Jackson County is, functionally, the home county of Kansas City. The downtown core, most of the city’s historic neighborhoods, the stadiums of the Kansas City Chiefs and Kansas City Royals, and the 18th & Vine and Crossroads districts all sit within its boundaries. Its dual-seat arrangement encodes a piece of KC history in plain sight — the early-frontier primacy of Independence as a trailhead, later overtaken by the railroad-driven rise of Kansas City — and its Truman legacy ties the county directly to one of the most consequential figures the region produced.

Sources

Footnotes

1. Wikipedia — “Jackson County, Missouri” (accessed June 2026). https://en.wikipedia.org/wiki/Jackson_County,_Missouri ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

2. U.S. Census Bureau — “QuickFacts: Jackson County, Missouri” (2020 census / population estimates). https://www.census.gov/quickfacts/fact/table/jacksoncountymissouri/PST045224 ↩ ↩²

3. National Park Service — “Historic Truman Courthouse – Harry Truman’s Office” (accessed June 2026). https://www.nps.gov/places/historic-truman-courthouse-harry-truman-s-office.htm ↩ ↩² ↩³

4. Harry S. Truman Library & Museum — “Jackson County Courthouse, Independence” (accessed June 2026). https://www.trumanlibrary.gov/education/student-resources/places/independence/jackson-county-courthouse-independence ↩