Sumner County is named for Jethro Sumner, who was an American colonist who defended North Carolina against the British in 1780.
Surrounding County Courthouses:
N – Simpson County, Kentucky and Allen County, Kentucky
E – Macon County and Trousdale County
S – Wilson County
W – Davidson County and Robertson County
Created: November 18, 1786 
County Seat:
Gallatin 1786 – present
County Courthouse – Gallatin
Location: 105 Public Square / Water Avenue
Built: 1939 – 1940
Style: Neo-Classical
Architect: Marr & Holman of Nashville
Contractor: W R Smith & Son of Nashville
Description: The building faces south and is a three story gray limestone and concrete structure. The building sits in the center of the Public Square in the center of Gallatin. .All the sides of the building are similar with vertical pilasters between the windows on the second and third stories. The central entrances are framed. A wide eave runs along the flat roof line. In the interior, there is a grand staircase ascending to the second story where the courtroom is located. The building houses the County Circuit Court, County Chancery Court and County Criminal Court of the 18th Judicial District. The building was a Work Projects Administration project. The building was renovated and remodeled from 1972 to 1975. The architect was Howard Nielson Thomas Miller Aldred Henry & O’Brien if Nashville and the contractor was Martin R Curtis Construction Company of Hendersonville.
See: The architect, Joseph Holman and Thomas Marr of Nashville, designed courthouses in Bedford County, Franklin County, Hardin County, Lauderdale County, Madison County, McNairy County, Obion County, Pickett County and Weakley County. They also designed the Tennessee Supreme Court in Nashville.
County Justice Center – Gallatin
Location: 117 West Smith Street / South Water Avenue
Built: 1970 – 1972
Style: Modern
Architect: Yearwood & Johnson, Inc.
Contractor: C T C Construction Company
Description: The building faces north and is a two story buff colored brick, concrete and glass structure. The building is located to the south of the courthouse in the center of Gallatin. The north front has glass walls on the first story with a central entrance. A wide horizontal concrete section runs at the roof line of the first story. The second story is recessed with several rectangular sections. The roof line is flat. The two courtrooms are located at the center of the first story. The building houses the County General Sessions Court and County Juvenile Court of the 18th Judicial District.
New County Justice Center – Gallatin
Location: 150 East Main Street / South Boyers Avenue
Built: Contruction has not started
Style: Modern
Architect: Justice Planning Associates
Contractor: Turner Corporation
Description: The building will face south and will be a five story red colored brick and concrete structure. The building will be located to the south of the courthouse in the center of Gattatin on the site of the First Baptist Church. The cost is $109,000,000..
History: The county was created in 1786 and Gallatin was selected as the county seat. The first courthouse was the home of Elmore Douglass used as a courthouse from 1788 to 1790. The second courthouse was built on the town square in 1803 to 1804. The third courthouse was built in 1839 and enlarged in 1867. The fourth and present courthouse was constructed in 1939 to 1940. The County Court Building was constructed in 1970 to 1972.
County Courthouse – Gallatin
County Justice Center – Gallatin
Photos taken 2012 and 2018