William Willard Preble Hall (May 9, 1820November 2, 1882) was an American lawyer and politician. He served as the 17th Governor of Missouri from 1864 to 1865 during the last years of the American Civil War. Early years Hall was born in Harpers Ferry, then in Virginia. He attended a private school in Baltimore, Maryland, and graduated from Yale University in 1839. He accompanied his father, John H. Hall, to Randolph County, Missouri, in 1840. He studied law and was admitted to the bar at Huntsville in 1841, commencing his law practice in Sparta in 1842. He was appointed circuit attorney in 1843 and served for several years. He was a presidential elector on the Democratic ticket in 1844. During the Mexican–American War, Hall enlisted as a private in the First Missouri Cavalry Regiment and later was promoted to lieutenant. He was appointed by General Kearny, together with Col. Alexander Doniphan, to construct the code of civil laws known as the Kearny code in both English and Spanish for the territory annexed from Mexico. In October he accompanied the famous Mormon Battalion on its march to California, thereafter he returned to Missouri and assumed his seat in Congress. Hall was elected as a Democrat to the Thirtieth, Thirty-first, and Thirty-second Congresses, serving from March 4, 1847, to March 3, 1853. During his Congressional service he was the chairman of the Committee on Private Land Claims (Thirty-first Congress), and of the Committee on Public Lands (Thirty-second Congress). He moved to St. Joseph, Missouri in 1854 and continued practicing law. He was an unsuccessful candidate for the United States Senate in 1856. Civil War In 1861 Hall was a member of the constitutional convention, which affirmed the policy of armed neutrality put forth by outgoing governor Robert Marcellus Stewart: that Missouri would remain in the Union but would not send troops or supplies to either side. Governor Claiborne Jackson and lieutenant governor Thomas C. Reynolds refused the call from President Abraham Lincoln for troops to put down secession, and conspired with the Confederacy. Union General Nathaniel Lyon seized the state capital and deposed Jackson. The constitutional convention reconvened, minus pro-Southern delegates, and declared the office of governor and lieutenant governor vacant. Hamilton Rowan Gamble was named provisional governor and Hall made lieutenant governor. Hall also became a brigadier general in the Missouri Militia, as formed under Union control. He commanded the northwestern