The following excerpt provided by Sheron Smith-Savage
DIED,
In Lincolnton, on the 15th ult., Col. WM. J. ALEXANDER, formerly a member of the Legislature from Mecklenburg, Superintendent of the Branch Mint, &c.
—Published in Fayetteville Semi-Weekly Observer (Fayetteville, North Carolina), March 5, 1857, p. 3


The following information provided by 7473a from NCpedia article:

William Julius Alexander, speaker of the North Carolina House of Commons, solicitor, and superintendent of the Charlotte branch of the U.S. Mint, was born in Salisbury, the son of William Alexander. He attended Poplar Tent Academy under the direction of a Reverend Dr. Robinson and was graduated from The University of North Carolina in 1816. After serving an apprenticeship under Archibald Henderson in Salisbury, Alexander was admitted to the bar in 1818. He married Catharine Wilson, daughter of Joseph Wilson, solicitor of the Sixth Circuit.
In 1826 Alexander entered public life as a Democratic representative from Mecklenburg County in the North Carolina House of Commons. He served five consecutive terms from 1826 to 1831 and two additional terms in 1833–34 and 1834–35. He was speaker in 1829–30, 1833–34, and 1834–35. He also served as a trustee of The University of North Carolina from 1827 until 1856. Following the death of his father-in-law in August 1829, he was appointed solicitor in his stead; he resigned in 1833. In 1835 he was defeated by Romulus M. Saunders for a seat on the superior court. In 1846 President James K. Polk, a fellow alumnus of the university and member of the same campus literary society, appointed Alexander superintendent of the U.S. branch mint in Charlotte, succeeding Greene W. Caldwell, who volunteered to fight in the war with Mexico. Alexander held this position as late as 1851. At his retirement he moved to Lincolnton, where he died.

References:
Kemp P. Battle, History of the University of North Carolina, 2 vols. (1907–1912).
Daniel Lindsey Grant, Alumni History of the University of North Carolina (1924).
Henry T. Shanks, ed., The Papers of Willie Person Mangum, 5 vols. (1950–1956).
William L. Sherrill, Annals of Lincoln County, North Carolina (1937).
John H. Wheeler, Historical Sketches of North Carolina (1851).
John H. Wheeler, Reminiscences and Memoirs of North Carolina and Eminent North Carolinians (1884).
https://www.ncpedia.org/biography/alexander-william-julius

The following excerpt provided by Sheron Smith-Savage
DIED,
In Lincolnton, on the 15th ult., Col. WM. J. ALEXANDER, formerly a member of the Legislature from Mecklenburg, Superintendent of the Branch Mint, &c.
—Published in Fayetteville Semi-Weekly Observer (Fayetteville, North Carolina), March 5, 1857, p. 3


The following information provided by 7473a from NCpedia article:

William Julius Alexander, speaker of the North Carolina House of Commons, solicitor, and superintendent of the Charlotte branch of the U.S. Mint, was born in Salisbury, the son of William Alexander. He attended Poplar Tent Academy under the direction of a Reverend Dr. Robinson and was graduated from The University of North Carolina in 1816. After serving an apprenticeship under Archibald Henderson in Salisbury, Alexander was admitted to the bar in 1818. He married Catharine Wilson, daughter of Joseph Wilson, solicitor of the Sixth Circuit.
In 1826 Alexander entered public life as a Democratic representative from Mecklenburg County in the North Carolina House of Commons. He served five consecutive terms from 1826 to 1831 and two additional terms in 1833–34 and 1834–35. He was speaker in 1829–30, 1833–34, and 1834–35. He also served as a trustee of The University of North Carolina from 1827 until 1856. Following the death of his father-in-law in August 1829, he was appointed solicitor in his stead; he resigned in 1833. In 1835 he was defeated by Romulus M. Saunders for a seat on the superior court. In 1846 President James K. Polk, a fellow alumnus of the university and member of the same campus literary society, appointed Alexander superintendent of the U.S. branch mint in Charlotte, succeeding Greene W. Caldwell, who volunteered to fight in the war with Mexico. Alexander held this position as late as 1851. At his retirement he moved to Lincolnton, where he died.

References:
Kemp P. Battle, History of the University of North Carolina, 2 vols. (1907–1912).
Daniel Lindsey Grant, Alumni History of the University of North Carolina (1924).
Henry T. Shanks, ed., The Papers of Willie Person Mangum, 5 vols. (1950–1956).
William L. Sherrill, Annals of Lincoln County, North Carolina (1937).
John H. Wheeler, Historical Sketches of North Carolina (1851).
John H. Wheeler, Reminiscences and Memoirs of North Carolina and Eminent North Carolinians (1884).
https://www.ncpedia.org/biography/alexander-william-julius