Question: What is the capital of the county where Robert Johnson Henderson was born?

full_context: Document 1: Joseph Spencer: Spencer was born in East Haddam, Connecticut. Spencer was the son of Isaac and Mary (née Selden) Spencer. He was the great-grandson of Gerard and Hannah Spencer, who were part of the first settlers of East Haddam in 1662.
Document 2: Newton County Courthouse (Georgia): Newton County Courthouse is a historic county courthouse in Courthouse Square in Covington, Georgia, the county seat of Newton County, Georgia. The courthouse was designed by Bruce & Morgan in a Second Empire architecture style and built in 1884. It was constructed on the same site as a previouse county courthouse building that burned down on December 31, 1883. The building was added to the National Register of Historic Places on September 18, 1980.
Document 3: Crawford County Courthouse (Ohio): The Courthouse of Crawford County, Ohio, is a landmark of the county seat, Bucyrus, Ohio. The courthouse was built in 1854 on East Mansfield Street by architect Harlan Jones and was added to the National Register of Historic Places on 1985-02-28 as a part of the Bucyrus Commercial Historic District.
Document 4: Hudson County Courthouse: The courthouse was used as the primary seat of government for Hudson County from its opening on September 20, 1910 until the construction of the Hudson County Administration Building in 1966. The courthouse was vacant for many years and was scheduled for demolition. The building was added to the National Register of Historic Places on August 25, 1970. Restoration began in the mid-1970s, and the building was reopened in 1985. In 1984, the Hudson County Board of Chosen Freeholders renamed the building in honor of Supreme Court Justice William J. Brennan Jr. The restoration of the courthouse was acknowledged by a Victorian Society in America Preservation Award in 1988.
Document 5: Louis Agassiz Shaw II: Shaw was born to Robert Gould Shaw II and Mary Hannington; the Shaws were a wealthy and influential Boston family. His father was a cousin of Colonel Robert Gould Shaw, noted for leading an African-American regiment in the Union Army during the Civil War.
Document 6: Old Horry County Courthouse: Old Horry County Courthouse, now known as Conway City Hall, is a historic courthouse building located at Conway in Horry County, South Carolina. It was built between 1824 and 1825 and reputedly designed by Robert Mills (1781-1855). It is a two-story Classical Revival brick building. It features an extended pediment supported by Doric order columns that shelters a second story portico which does not extend the full width of the façade.
Document 7: Newton Edmunds: Newton Edmunds was born in Hartland, New York on May 31, 1819. In 1832, he moved with his family to Michigan. The Edmunds family was involved with politics, associating with the Free Soilers before affiliating with the Republican Party. Newton Edmunds' brother, C. E. Edmunds, was Commissioner of the United States Land Office. Newton Edmunds was appointed as chief clerk in the surveyor-general's office, resulting in Edmunds' arrival in Dakota Territory in 1861. On August 30, 1862, Edmunds was elected as eighth corporal of Company A of the Dakota Militia, following the Santee uprising.
Document 8: Benton County Courthouse (Arkansas): The Benton County Courthouse is a courthouse in Bentonville, Arkansas, United States, the county seat of Benton County, built in 1928. It was listed on the National Register of Historic Places in 1988. The courthouse was built in the Classic Revival style by Albert O. Clark and anchors the east side of the Bentonville Town Square.
Document 9: Jackson County Courthouse (Jacksonville, Oregon): The Jackson County Courthouse is a former county courthouse in Jacksonville, Oregon, United States, built in 1883. The courthouse is a contributing property of the Jacksonville Historic District, which is listed on the National Register of Historic Places (NRHP). It was formerly the Jacksonville Museum owned by Jackson County and operated by the Southern Oregon Historical Society (SOHS), which also managed several other historic properties in Jacksonville. The museum in the courthouse closed in 2006 because of lack of funding. Ownership of the historic courthouse was transferred to the City of Jacksonville in 2012. The SOHS still operates Hanley Farm in Central Point and a research library in Medford.
Document 10: John Wellborn Root: John Wellborn Root was born in 1850 in Lumpkin, Georgia, the son of Sidney Root, a planter, and his wife, Mary Harvey Clark. He was named after a maternal uncle, Marshall Johnson Wellborn. Root was raised in Atlanta, where he was first educated at home. When Atlanta fell to the Union during the American Civil War, Root's father sent young Root and two other boys on a steamer to the United Kingdom, where his father, Sidney, had a shipping business based in Liverpool, England. His mother and sister went to Cuthbert, Georgia.
Document 11: Glascock County Courthouse: Glascock County Courthouse is a courthouse on Main Street in Gibson, Georgia, the county seat of Glascock County. The first county courthouse was built in 1858 with a donation from William Gibson, namesake of the county seat. It was removed for use as a residence when the currently used courthouse was built in 1919. The courthouse was designed by J.W. McMillian & Son. It was added to the National Register of Historic Places on September 18, 1980.
Document 12: John Seward Johnson I: John Seward Johnson I (July 14, 1895 – May 23, 1983) was one of the sons of Robert Wood Johnson I (co-founder of Johnson & Johnson). He was also known as J. Seward Johnson Sr. and Seward Johnson. He founded the Harbor Branch Oceanographic Institution (HBOI), and was the grandfather of Jamie Johnson, who directed the documentary "Born Rich".
Document 13: Robert Johnson Henderson: Robert Johnson Henderson (November 12, 1822 – February 3, 1891) was a Confederate States Army colonel during the American Civil War (Civil War). His obituary stated that he was made a brigadier general by General Joseph E. Johnston, after Johnston witnessed Henderson making a desperate charge at the Battle of Bentonville, North Carolina, on March 10, 1865. At the suggestion of his divisional commanders, Henderson signed his parole as a brigadier general. Later, Henderson stated in his pardon application that he had been recommended for promotion to brigadier general but had never received a commission. Henderson commanded a brigade for several weeks at the end of the war but never was officially appointed by Confederate President Jefferson Davis and confirmed by the Confederate States Senate to brigadier general rank.
Document 14: Robert Johnson Henderson: Robert Johnson Henderson was born in Newton County, Georgia on November 12, 1822. His parents were Isaac and Ruth Shepherd (Johnson) Henderson. Isaac Henderson, who was born in Maryland, was a wealthy planter and a representative in the state legislature.
Document 15: Merrick County Courthouse: The Merrick County Courthouse was built from 1911 to 1913 in Central City, Nebraska, United States. Designed in the Classical Revival style by architect William F. Gernandt, it was built at a cost of $100,000. In 1990, it was listed in the National Register of Historic Places, but was removed from the Register in 2014.
ground_truth: Covington
sub_queries: Which city was the birthplace of Robert Johnson Henderson? Answer: Newton County
Newton County >> capital Answer: Covington