When was Buchanan County founded?

Buchanan County was founded in 1838, and named after James Buchanan.

What is the county seat of Buchanan County?

The county seat of Buchanan County is St. Joseph.

Is there an online parcel map for Buchanan County?

Yes. A public source publishes a parcel map of 40,078 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Buchanan County's boundary or name changed?

Buchanan County was created in 1838. Since then the Atlas of Historical County Boundaries records 4 later changes, chiefly involving Andrew County, Holt County and Nodaway County.

Is my lot in a flood zone?

We do not have flood maps for Buchanan County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

County · code 29021

Buchanan CountyMissouri

Buchanan County, Missouri, covers 408.2 square miles and has its county seat in St. Joseph. The county was created on December 31, 1838, from areas that included present-day Kansas territory, and was named after James Buchanan.

Founded1838
County seatSt. Joseph
Named forJames Buchanan
Land area408 sq mi + 6.9 sq mi water
Population84,793 2020 Census
Parcels mapped40,078 checked 16 October 2026

Open the free map Click any parcel in Buchanan County: acreage, parcel id, address and who publishes the map. No sign-in.

Updated 20 October 2026

Census outline · seat marked

History

Founded in 1838

An old deed may name a county that no longer exists, or a boundary that has since moved.

Buchanan County was created in 1838 from non-county area, including territory that later became part of Kansas due to shifts in the course of the Missouri River. In 1839, non-county area 31 (Territory of Neatawah) was attached to Buchanan, but parts were lost in 1841 when Andrew and Nodaway counties were created. In 1950, Buchanan County exchanged territory with Kansas to accommodate changes in the Missouri River's course that had occurred in 1944.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries.

1838
Buchanan County created Buchanan created from Non-County Area 12. 31 December 1838 · Mo. Laws 1838-1839, pub., pp. 23-25
1839
Changed Non-County Area 31 (Territory of Neatawah) attached to Buchanan "for civil and military purposes." 11 February 1839 · Mo. Laws 1838-1839, pub., pp. 21-22
1841
Lost territory Buchanan lost parts of attached Non-County Area 31 (Territory of Neatawah) to creation of Andrew and Nodaway (original).
to Andrew to Nodaway to Holt
29 January 1841 · Mo. Laws 1840-1841, pub., secs. 1, 4/pp. 32-33
1841
Changed Non-County Area 31 (Territory of Neatawah) detached from Buchanan, attached to Andrew "for civil and military purposes."
Andrew
12 February 1841 · Mo. Laws 1840-1841, pub., p. 40
1950
Exchanged territory Buchanan (Missouri) exchanged with the state of Kansas to accommodate changes in the course of the Missouri River that occurred in 1944; Buchanan eliminated from present Kansas. The change took effect 3 August 1950 after the United States Congress approved a joint resolution establishing the permanent boundary between Kansas and Missouri along the Missouri River from 40 degrees north latitude to the Kansas River. Minor shifts in the Missouri River boundaries of other Missouri counties are not mapped. 3 August 1950 · Kans. Laws 1949, 53d leg., chs. 196, 510/pp. 293-294, 837-838; Mo. Laws 1949, S.B. 141, p. 311; U.S. Stat., vol. 64, ch. 519 [1950]/p. 397

Land and parcels

What the maps cover in Buchanan

Who publishes each layer, how good it is, and when we last checked.

Parcels Good enough

Lot lines and tax-map numbers for 40,078 parcels. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 27 January 2026 · checked 16 October 2026
Address points Missing

No public address points layer found for Buchanan County yet.
Buildings Reference

Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026

Official: from the office that keeps the record
Good enough: a reliable statewide or national copy
Fallback: a guide only; check the official record
Missing: nothing public found yet

People and land

Buchanan by the Census

Population

84,793 2020 Census count

Housing units

38,258 2020 Census count

Land area

408 square miles

Water area

6.9 square miles

People per sq mi

208 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

Rules and offices

Buchanan County's official site

We have found the county's site but not its offices yet; start there.

County government

County government
The official website of Buchanan County.
co.buchanan.mo.us

See your own lot on these maps

Open Buchanan County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.

Open the free map no sign-in Pro early access

Questions

Common questions about Buchanan County

When was Buchanan County founded?: Buchanan County was founded in 1838, and named after James Buchanan.
What is the county seat of Buchanan County?: The county seat of Buchanan County is St. Joseph.
Is there an online parcel map for Buchanan County?: Yes. A public source publishes a parcel map of 40,078 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Buchanan County's boundary or name changed?: Buchanan County was created in 1838. Since then the Atlas of Historical County Boundaries records 4 later changes, chiefly involving Andrew County, Holt County and Nodaway County.
Is my lot in a flood zone?: We do not have flood maps for Buchanan County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby