De Soto is a city on the Kansas (Kaw) River in northwestern Johnson County and southeastern Leavenworth County, Kansas, in the Kansas City Metropolitan Area. Platted in 1857 and named for the Spanish explorer Hernando de Soto, the town spent most of its history as a modest river-and-rail community — then exploded into a national story in July 2022, when Panasonic announced a $4 billion electric-vehicle battery plant on the former Sunflower Army Ammunition Plant site, now Astra Enterprise Park, projected to create 4,000 direct jobs.1

Overview

CountiesJohnson and Leavenworth, Kansas
Named forHernando de Soto (16th-century Spanish explorer)1
PlattedSpring 18571
IncorporatedOctober 1, 18971
Population6,118 (2020); est. 7,083 (2025)1
Major siteAstra Enterprise Park (former Sunflower Army Ammunition Plant) — future Panasonic EV-battery factory1
School districtUSD 232 (De Soto High School; Mill Valley High School in Shawnee)1

Geography

De Soto sits along the north bank of the Kansas (Kaw) River in the K-10 highway corridor between Lawrence to the west and Lenexa/Olathe to the east, straddling the Johnson–Leavenworth county line. The K-10 corridor and the river together frame De Soto’s position as the western gateway of suburban Johnson County.1

History

Indigenous and early settlement

The land was settled from about 1828 by the Black Bob band of Shawnee, who migrated west along the Kansas River. The Anglo-American town was officially platted in spring 1857 and named for Hernando de Soto, the sixteenth-century Spanish explorer who led the 1539–1542 expedition through the American Southeast. De Soto was incorporated as a city on October 1, 1897.1

Sunflower Army Ammunition Plant

The Sunflower Ordnance Works was established on May 11, 1942, when the U.S. government signed an operating contract with Hercules Powder Company for a smokeless-powder and propellant facility on roughly 10,747 acres south of De Soto. First propellant was produced ten months later. During World War II the site became the world’s largest smokeless-powder plant, producing over 200 million pounds of propellants and employing as many as 12,067 workers at wartime peak — a workforce that dwarfed De Soto’s civilian population and drove the construction of on-site worker housing (the vanished community of Prairie Center was condemned, razed, and its residents and cemetery plots relocated to Eudora and De Soto).234

The plant was renamed the Sunflower Army Ammunition Plant (SFAAP) on August 1, 1963, and continued producing propellants for small arms, cannon, and rocket applications through the Korean and Vietnam eras. Production ceased in 1992; the Army declared the property excess in 1998.23

Astra Enterprise Park

In 2005 the Army transferred the site to Sunflower Redevelopment LLC (managing members: Kessinger Hunter, RESIGHT Holdings, and Kansas City-based Midland Properties), which took on the environmental remediation obligation. Cleanup of contaminated soils, groundwater, and legacy pesticides has been underway ever since; the Army expects the majority of remediation to be complete by 2028.56

De Soto annexed roughly 6,000 acres of the former plant site in 2022 and rebranded it Astra Enterprise Park, a name drawn from the Kansas state motto Ad astra per aspera. The master plan allocates approximately 2,700 acres for parks, 1,350 acres for industrial development, 3,000 acres for a utility-scale solar park, and 2,500 acres for multi-use/light-industrial development. Digital Realty is separately exploring a large data-center campus (Astra North + Astra South, roughly 1,400 acres) on the site.78

Panasonic Energy EV battery plant

In July 2022, Panasonic Energy announced a ~$4 billion lithium-ion EV-battery factory on approximately 605 acres inside Astra Enterprise Park — the largest economic-development project in Kansas state history. Ground was broken November 2022.910

Mass production of 2170-format cells began at the Kansas Factory in early 2025, and Governor Laura Kelly presided over the grand opening on July 14, 2025. At opening, Panasonic had hired approximately 1,000 staff of a projected ~4,000-worker full workforce. The plant is targeting an annual capacity of approximately 32 GWh; combined with Panasonic’s Nevada facility, U.S. capacity is projected to reach ~73 GWh when fully ramped, supplying lithium-ion cells to Tesla and other EV customers.111213

Demographics and growth

De Soto’s 2020 census population was 6,118, with a 2025 estimate of ~7,083 — but the Panasonic build-out, USD 232 school growth, and Astra Enterprise Park land absorption are widely expected to reshape that trajectory sharply upward. De Soto was already the second-fastest-growing city in the Kansas City metro area as of 2019, before the Panasonic announcement.114

Institutions

De Soto USD 232

Unified School District 232 is headquartered in De Soto at 35200 West 91st Street and serves the city plus roughly 60% of Shawnee, 40% of Lenexa, a fraction of Olathe, and surrounding rural territory. The district enrolls approximately 7,500 students across 14 campuses, and Niche’s 2026 rankings place it #2 among Kansas school districts and in the top 3% nationally. High schools are De Soto High School (De Soto) and Mill Valley High School (Shawnee); middle schools include Lexington Trails, Monticello Trails, and Mill Creek (Shawnee).1516

Sources

See also

Footnotes

  1. Wikipedia — “De Soto, Kansas.” — accessed 2026-08-13. Asserts: location on the Kansas River in Johnson and Leavenworth counties; part of Kansas City Metropolitan Area; platted spring 1857; naming for Hernando de Soto; incorporation October 1, 1897; Black Bob band of Shawnee settlement from ~1828; 2020 census population 6,118; 2025 estimate 7,083; “second fastest-growing city in the Kansas City metro area as of 2019”; USD 232 with De Soto High School and Mill Valley High School (Shawnee). ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10

  2. Legends of Kansas — “Sunflower Ordnance Works & Village, Kansas.” — accessed 2026-08-13. Asserts: 10,747-acre site; operating contract with Hercules Powder Co. signed May 11, 1942; first propellant produced ten months later; renamed Sunflower Army Ammunition Plant on August 1, 1963; the vanished Prairie Center community’s residents and cemetery plots relocated to Eudora and De Soto. ↩ ↩2

  3. Kansas Department of Health and Environment — “Sunflower Army Ammunition Plant.” — accessed 2026-08-13. Asserts: state environmental oversight of the SFAAP remediation program. ↩ ↩2

  4. Wikipedia — “Sunflower Army Ammunition Plant.” — accessed 2026-08-13. Asserts: over 200 million pounds of propellants produced during WWII; peak wartime workforce of 12,067; world’s largest smokeless-powder plant; production ceased 1992; declared excess 1998. ↩

  5. KSHB 41 — “US Army expects cleanup of former Sunflower Army Ammunition Plant to be mostly complete in 2028.” — accessed 2026-08-13. Asserts: Army has been cleaning up the site since 2005; targeting majority-complete remediation by 2028. ↩

  6. City of De Soto — “History — Sunflower Army Ammunition Plant.” — accessed 2026-08-13. Asserts: city-side history of the SFAAP site and 2005 transfer to Sunflower Redevelopment LLC. ↩

  7. FOX4 Kansas City — “Sunflower Army Ammunition Plant renamed Astra Enterprise Park.” — accessed 2026-08-13. Asserts: De Soto annexed 6,000 acres in 2022 and renamed the site Astra Enterprise Park, drawing from the Kansas motto Ad astra per aspera. ↩

  8. City of De Soto — “Astra Enterprise Park.” — accessed 2026-08-13. Asserts: master-plan land allocations — 2,700 acres parks, 1,350 acres industrial, 3,000 acres utility-scale solar, 2,500 acres multi-use/light industrial; Digital Realty data-center project (Astra North + Astra South ~1,400 acres); Panasonic footprint ~605 acres. ↩

  9. Panasonic North America — “Panasonic Energy Breaks Ground on EV Battery Factory in Kansas.” — accessed 2026-08-13. Asserts: November 2022 groundbreaking at the De Soto site; ~$4 billion investment. ↩

  10. City of De Soto — “Panasonic Electric Vehicle Battery Facility.” — accessed 2026-08-13. Asserts: city-side profile of the Panasonic facility inside Astra Enterprise Park; ~4,000 projected workforce. ↩

  11. Panasonic North America — “Panasonic Energy Begins Mass Production at New Automotive Lithium-ion Battery Factory in Kansas, Aiming for Annual Capacity of 32 GWh.” — accessed 2026-08-13. Asserts: mass production of 2170 cells has begun at the Kansas Factory; targeting ~32 GWh annual capacity; combined U.S. capacity (with Nevada) approximately 73 GWh when ramped; targeting 50% local supply chain integration. ↩

  12. Kansas Department of Commerce — “Governor Kelly Celebrates Grand Opening of Panasonic EV Battery Manufacturing Facility in De Soto.” — accessed 2026-08-13. Asserts: grand opening held July 14, 2025, in De Soto; state’s largest economic-development project. ↩

  13. Ingram’s — “De Soto $4B Panasonic Plant Officially Begins Mass Production.” — accessed 2026-08-13. Asserts: ~1,000 staff hired at opening; $4 billion investment; mass production start. ↩

  14. KCUR — “Panasonic’s battery plant is already transforming De Soto, Kansas. It’s only halfway built.” — accessed 2026-08-13. Asserts: housing and demographic pressure on De Soto driven by Panasonic build-out. ↩

  15. USD 232 — “School Directory.” — accessed 2026-08-13. Asserts: district roster including De Soto HS, Mill Valley HS, Mill Creek MS, Lexington Trails MS, Monticello Trails MS; headquartered at 35200 W 91st St, De Soto. ↩

  16. Wikipedia — “De Soto USD 232.” — accessed 2026-08-13. Asserts: service area covers De Soto, ~60% of Shawnee, ~40% of Lenexa, and part of Olathe; approximately 7,500 students across 14 campuses; most students reside in Shawnee. ↩

See also

Categories
  • Concept
  • Place
  • Neighborhood
  • Antebellum
  • Modern

On the record — ks.city/wiki/neighborhoods/de-soto-ks · last revised 2026-08-13