Mercer County, Illinois Genealogy Records

Which records survive from Mercer County, the years each set covers, and where to find them.

Formed
1825
County seat
Aledo
Fulton CountyHancock CountyHenderson CountyHenry CountyKnox CountyMcDonough CountyPeoria CountyRock Island CountyStark CountyTazewell CountyWarren CountyWhiteside CountyMercer CountyHendersonHenryKnoxPeoriaRock IslandStarkWarrenMercer
Mercer CountyToday's boundaries · U.S. Census Bureau

Records that survive

These are the record series from Mercer County held by the Illinois Regional Archives Depository (IRAD) system, with the earliest and latest years. A span can include gaps. They include county, township and city records. This county's are held at Western Illinois University in Macomb.

Deeds and land

  • Deed Index1834–1901
  • Deed Record1834–1901
  • Entry Books1834–1954

Other records

  • Almshouse Registers1859–1986

Search the IRAD database for this county

Source: Illinois State Archives, Local Government Records Database (choose the county to see every series and its accession number). Contact the depository before you visit. Illinois began statewide registration of births and deaths in 1916.

Where to find the records

  • Find Mercer County's official website

    We haven't checked this county's website yet, so this opens a web search. Look for an address ending in .gov, then find the county clerk, the recorder of deeds and the clerk of the circuit court.

  • The county clerk

    Births, deaths and marriages registered in the county.

  • The recorder of deeds

    Deeds, mortgages and other land records (in some counties the county clerk is also the recorder).

  • The clerk of the circuit court

    Probate (wills and estates), divorces and civil and criminal cases.

  • The Illinois State Archives

    In Springfield, with older county records at its regional depositories (IRAD) on university campuses.

  • Illinois Regional Archives Depository (IRAD) systemfree

    The State Archives' regional depositories, which hold older county, township and city records; search its Local Government Records Database by county.

  • FamilySearch Catalogfree

    Search by place for "Illinois, Mercer" to find filmed and digitized records, many viewable free online with a FamilySearch account.

Offices change their hours and access rules; call before you visit.

Boundaries and parent counties

Formed from: Land not yet in any county

Later formed partly from Mercer County: Jo Daviess County

MorganFultonNon-County Area 5FayetteSangamonNon-County Area 6PikeNon-County Area 3MercerMercerNon-County Area 3FultonNon-County Area 5FayetteSangamon
Mercer as created in 1825Where its land was the day beforeToday's boundaryBoundaries: Newberry Library, Atlas of Historical County Boundaries

Records stay with the county that created them. If your ancestor lived here before 1825, search the parent county. The Atlas of Historical County Boundaries shows each boundary change.

Research tip

Illinois began statewide registration of births and deaths in 1916; counties kept registers earlier, often from 1877 or 1878. The Illinois Statewide Marriage Index, from the State Archives, covers many marriages from 1763 to 1900.