The Blue Ridge mountains form the southern end of the Appalachian chain and begin just south of Union County.

The OverHill Cherokee Indians were the first settlers in Union County. Union County's first white man was a Mr. Duncan, who took a Cherokee wife. The first courthouse was built in 1835 of logs. It was destroyed by fire in 1859 and replaced, but it burned in 1898. It was rebuilt of brick and still stands today in the middle of the town square as a museum.

Originally this area was part of Cherokee County, but in 1832 Cherokee County was divided into ten counties: Bartow, Cherokee, Cobb, Floyd, Forsyth, Gilmer, Lumpkin, Murray, Paulding and Union. In the Lottery of 1832 the government granted land lots (160 acres) and gold lots (40 acres). 

Between 1828 and the Cherokee Indian "total removal" in 1841, relations got violent between the Cherokees and the white settlers.   Blairsville, the county seat of Union County, was named during the time of the Indian removal.  There are two stories about the naming of the City.  One says that it was named for Frank Blair, a Washington, DC newspaper editor.  Another story says it is named for Captain James Blair, who actively represented the white Georgians with the Cherokees.  Blairsville was incorporated in 1847. 

In 1848 there were 5 post offices in Union County: Blairsville, Ivy Log, Polk, Shady Grove and Young Cane. In 1848 the taxes for the County totaled $878.80 and the population was 5,812. Most land was $3-$5 per acre.

In 1854 the western part of Union County was given to Fannin County, In 1856 the southern tip was given to Gilmer County and an eastern section was given to Towns County.

Union County was not named for its support of the north in the Civil War. George M. Troup, Georgia Governor (1823-1827), verbally attacked the U. S. government and threatened to declare war on the United States if it interfered with his policy of surveying land held by Creek Indians and opening the land to white settlers. Governor Troup's most powerful support came from northern Georgia, where gold had been discovered. A political party emerged, calling themselves the "Union Party".

After the land was taken from the Indians, the Union Party went out of existence, but during the time of its power, this part of north Georgia was named Union County, 28 years before the start of the Civil War, or War Between the States, as it is called in the South.

Gold was mined from Coosa Creek and from the mountains nearby and the total value of gold removed was estimated at $2-million. Gold was mined here from before 1830 up to the start of World War II in 1941. Old mines can still be located.

By 1850 Blairsville had a courthouse, a jail, a school, a trailer, a cabinetmaker, two hotels, and six stores. Population was about 150. In Union County were 11 saw mills, 25 grist mills, 7 distilleries, 1 iron works, and 1 merchant mill under construction.

The Choestoe Baptist Church was the first church of any kind in Union County and it has written records that go back to 1834. Methodist circuit-riding preachers were at work here by 1840.

TVA electric power came into Union County in the 1930's, making the biggest change in the mountain life-style ever. Sewing factories gave employment to many of the women and some men.

Union County is the birthplace of current U. S. Senator Zell Miller (D).  Miller served Georgia as State Senator, Lieutenant Governor and Governor before becoming U. S. Senator.

The "Zell Miller" Appalachian Developmental Highway (GA 515) brought good road transportation in 1985, bringing tourism as a major employer of Union County workers, and allowing easy commuting by Union County workers to jobs closer to Atlanta. The new super-highway also brought the growth of the retirement housing industry to Union and Towns Counties. Construction of housing continues as a large employer of men.

Blairsville was rated among the "top ten places for retirement" in a Wall Street Journal article in 1994 for reasons of low crime and low cost of living.

Since 1994, twelve new industries and about 100 new businesses have located in Union County.