Union County was created from Ninety Six District in 1785 and was part of the Pinckney District from 1791 to 1800 when it became a separate district. Later, in 1897, part of it went to form Cherokee County. It was named for the old Union Church, which served both the Presbyterian and Episcopal congregations in the area. The church was erected in 1765 near the present day town of Union, the county seat. 1800 and became a separate district when Pinckney was dissolved in 1800.
The first settlers to this area were migrating Scotch-Irish families from Virginia and Pennsylvania.
During the Revolutionary war, many skirmishes occurred in the county, including the battle of Musgrove's Mill on August 18, 1780 and the battle of Blackstocks on November 20, 1780.
Early settlers: Francis Welchel, Dominic Hollan, Francis Hollam, Robert Lusk, Phillip Holcom, Thomas Brandon (1741-1802), Joseph McJunkin (1755-1846), William Henry Wallace (1827-1905), and others.
Index to Union County Minute Book A of the Probate Court (1783-1791)
Index to Union County Will Book A (1777-1814)
Index to Union County Will Book A (1815-1849)
Transcripts of Union County Wills (1777-1800)
Testators: William Blackstock, Joseph Hughes, Thomas B. Hunt, James Kennedy,Joseph Lee, Daniel Prince, David Prince, James Savage, Capt. John Savage, Adam Fincher, Benjamin Holcombe, Benjamin Johnson, Benjamin Woodson, Charles Clanton, Charles Thompson, Daniel Comer, Daniel Howell, Daniel McBride, Daniel Nogher, David Chisolm, David Stockton, Edward Porter, Elijah Cooper, Elizabeth Cooper, Elizabeth Miller, Ephram Pucket, Francis Drake, George Crosley, George Harland, George Norman, Henry Clark, Isaac Gregory, James Addington, James Bankhead, James Benford, James Gibbs, James Hawkins, James Parnell, James Sims, James Thomas, James Townsend, James Woodson, Jeremiah Cooper, Jesse Paty, John Buford, John Clark, John Cole, John Harington, John Huey, John Jasper, John Taylor, John Wilson, Magnus Simonson, Mary Frost, Moses Weldon, Nathaniel Dabbs, Nathaniel Davis, Randolph Alexander, Rebecca Fincher, Renney Belue, Renney Belue, Jr., Robert Good, Robert Wallace, Samuel Cooper, Samuel Torbert, Solomon Whitsen, Susannah Bailey, Thomas Harris, Thomas Haslewood, Thomas Henderson, Thomas Layton, Thomas McDonald, Thomas Wright, Thomas Young, Turner Rountree, William Farr, William Hendley, William Lee, William McJunkin and William Plummer.