Carroll County is included in the Atlanta-Sandy Springs-Roswell, GA Metropolitan Statistical Area. It is located just east of the boundary with Alabama.
The lands of Lee, Muscogee, Troup, Coweta, and Carroll counties were ceded by the Creek people in the Treaty of Indian Springs (1825). This was a huge amount of land in Georgia and Alabama, the last remaining portion of the Creeks' territory, and it was ceded by William McIntosh, the chief of the Lower Creek and a member of the National Council. This cession violated the Law, the Code of 1818 that protected communal tribal land. The Creek National Council ordered the execution of McIntosh and other signatories to the treaty for what it considered treason.
He was killed at his plantation home, at what has been preserved as the McIntosh Reserve. Menawa and a force of 100-150 Law Defenders from Upper Town lands ceded in this treaty carried out the executions of two other men, including Samuel Hawkins, one of McIntosh's sons-in-law. Benjamin Hawkins, Jr., another son-in-law, was also named for execution but he escaped, and soon moved to East Texas with his wife and family. Both of the Hawkins brothers were sons of Benjamin Hawkins, the longstanding US Indian Supervisor of the Creek.
The boundaries of Carroll County were created by the Georgia General Assembly on June 9, 1826, but the county was not named until December 14, 1826. It was named for Charles Carroll of Baltimore, Maryland, at that time the last surviving signer of the U.S. Declaration of Independence, as was Carrollton, the county seat.
This county originally extended from the Chattahoochee River to the Alabama state line on the east and on the west, with its northern boundary at the Cherokee Nation, just north of present-day Interstate 20. As population increased, this land was divided into Carroll, Douglas, and Heard counties, and parts of Haralson and Troup counties. The portion that became Douglas County was once Campbell County which no longer exists (it was divided between Douglas and Fulton counties).
Because the county had few slaves compared to counties developed for cotton plantations, it was called the Free State of Carroll during the 1850s. Even before the cession of territory by the Cherokee in the late 1830s, some white settlers lived in the northern part of the county in the area of Villa Rica.
Carroll County was the site of Georgia's first Gold Rush.
For a time Carroll County was the home of Horace King (architect). King helped build Moore's Bridge over the Chattahoochee River at Whitesburg. Moores Bridge was burned by Union soldiers during the Civil War. During the War between the States, the county provided the Bowdon Volunteers and the Carroll Boys, which were a part of Cobb's Legion.
In February 2008 several tornadoes hit Carroll County, destroying several homes and damaging many more. On May 11, 2008 (Mother's Day) some of the same areas were hit by more tornadoes. The Mother's Day tornadoes destroyed and damaged many homes and businesses.
On September 21 2009, portions of Carroll County were flooded after eight days of heavy rainfall, resulting in multiple death. The flooding initially closed more than 60 highways and roads, and it destroyed a number of bridges. Early estimates of the damage totaled $22.0 million dollars.