Mercer County is named for Hugh Mercer, who was a physician and general during the American Revolutionary War and who died at the Battle of Princeton.
Surrounding County Courthouses:
E – Henry County and Knox County
S – Warren County and Henderson County
W – Louisa County, Iowa
Created: January 13, 1825 
County Seat:
Boston 1835 – 1837
Millersburg 1837 – 1857
Aledo 1857 – present
County Courthouse – Aledo
Location: 100 SE 3rd Street / South College Avenue
Built: 1894 – 1895
Style: Romanesque
Architect: Mifflin Emien Bell
Contractor: L L Leach & Sons
Description: The building faces north and is a three story course Beria sandstone structure. The building is located on spacious landscaped grounds in the center of Aledo. The north front of the square shaped building has two small towers with turrets rising on either side of the first story portico. The east and west wings extend from the main building. On the center of the roof is a large square clock tower with turrets and peaked roof.
See: The architect, Mifflin Emien Bell also designed the courthouse in DuPage County, and courthouses in Iowa in Marion County and in Wisconsin in Monroe County.
History: The county was created in 1825 and was attached to Schuyler County until 1826, then to Peoria County until 1831, and finally to Warren County until organized in 1835 when Boston was selected as the county seat. In 1837, the county seat was moved to Millersburg and then to Keithsburg in 1847. In 1856, the county seat was moved to Aledo and the first courthouse was built. The second and present courthouse was constructed in 1894 to 1895 at a cost of $60,000.
County Courthouse – Aledo
Photos taken 2008