William Preston (Kentucky)

William Preston III
Brig. Gen. William Preston
Born	(1816-10-16)October 16, 1816 Louisville, Kentucky
Died	September 21, 1887(1887-09-21) (aged 70) Louisville, Kentucky
Buried at	Cave Hill Cemetery, Louisville
Allegiance	United States of America Confederate States of America
Service/branch	Kentucky Militia United States Army Confederate States Army
Years of service	1846–1848 1861–1865 (CSA)
Rank	Lieutenant Colonel (USV) Brigadier General (CSA)
Unit	4th Regiment Kentucky Volunteers
Commands held	Preston's Brigade Preston's Division
Battles/wars	Mexican–American War American Civil War
Other work	lawyer, politician, diplomat

William Preston (October 16, 1816 – September 21, 1887) was an American lawyer, politician, and ambassador. He also was a brigadier general in the Confederate Army during the American Civil War.

Preston, the grandson of Col. William Preston—the namesake of Prestonville, Kentucky—was born in Louisville, Kentucky. Francis Preston was his uncle. His sister Henrietta married Albert S. Johnston in 1829. He pursued preparatory studies and graduated from St. Joseph's College in Kentucky. He attended Yale College in 1835 and graduated from the law department of Harvard University in 1838. After graduation from Harvard, Preston was admitted to the bar and commenced practice in Louisville in 1839.

He served as lieutenant colonel of the 4th Kentucky Volunteers in the Mexican–American War from 1847 to 1848. After the war, he was a delegate to the State constitutional convention in 1849 and a member of the Kentucky House of Representatives in 1850. Subsequently, he served in the State senate 1851–1853. He was elected as a Whig to the Thirty-second Congress to fill the vacancy caused by the resignation of Humphrey Marshall and reelected to the Thirty-third Congress and served from December 6, 1852, to March 3, 1855. He stood again for another term in 1854 but was unsuccessful. President James Buchanan appointed Preston as Envoy Extraordinary and Minister Plenipotentiary to Spain in 1858. He resigned as ambassador in 1861 at the outbreak of the Civil War.