When was Carroll County founded?

Carroll County was founded in 1836, formed from Baltimore County and Frederick County, and named after Charles Carroll of Carrollton.

What is the county seat of Carroll County?

The county seat of Carroll County is Westminster.

Is there an online parcel map for Carroll County?

Yes. Carroll County publishes a parcel map of 70,060 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.

Has Carroll County's boundary or name changed?

Carroll County was created in 1836 from Baltimore County and Frederick County. The Atlas of Historical County Boundaries records no boundary change since.

Is my lot in a flood zone?

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

County · code 24013

Carroll CountyMaryland

Carroll County is in Maryland and has its county seat in Westminster. It was created on January 19, 1836.

Founded1836
County seatWestminster
Named forCharles Carroll of Carrollton
Land area448 sq mi + 5.1 sq mi water
Population172,891 2020 Census
Parcels mapped70,060 checked 15 October 2026

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

Updated 19 October 2026

Census outline · seat marked

History

Formed in 1836 from Baltimore County and Frederick County

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

Carroll County was created from Baltimore County and Frederick County on January 19, 1836. It was named after Charles Carroll of Carrollton.

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

1836
Carroll County created Carroll created from Baltimore and Frederick.
from Baltimore from Frederick
19 January 1836 · Md. Laws 1835, ch. 256, sec. 1; Md. Laws 1836, ch. 19

Land and parcels

What the maps cover in Carroll

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

Parcels Good enough

Lot lines and tax-map numbers for 70,060 parcels from Carroll County. Drawn for tax purposes: usually within a few feet of a survey, but not a survey.
edited 21 September 2026 · checked 15 October 2026
Address points Missing

No public address points layer found for Carroll 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

Carroll by the Census

Population

172,891 2020 Census count

Housing units

65,793 2020 Census count

Land area

448 square miles

Water area

5.1 square miles

People per sq mi

386 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

Carroll 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 Carroll County.
carrollcountymd.gov

See your own lot on these maps

Open Carroll 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 Carroll County

When was Carroll County founded?: Carroll County was founded in 1836, formed from Baltimore County and Frederick County, and named after Charles Carroll of Carrollton.
What is the county seat of Carroll County?: The county seat of Carroll County is Westminster.
Is there an online parcel map for Carroll County?: Yes. Carroll County publishes a parcel map of 70,060 parcels, rated good enough here. You can click any parcel on it in Parcel Chart's free map, no sign-in needed.
Has Carroll County's boundary or name changed?: Carroll County was created in 1836 from Baltimore County and Frederick County. The Atlas of Historical County Boundaries records no boundary change since.
Is my lot in a flood zone?: We do not have flood maps for Carroll County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby