American Civil War David Rice Atchison (August 11, 1807 – January 26, 1886) was a mid-19th-century Democratic[1] United States Senator from Missouri.

[2][3] Atchison, owner of many slaves and a plantation, was a prominent pro-slavery activist and Border Ruffian leader, deeply involved with violence against abolitionists and other free-staters during the "Bleeding Kansas" events that preceded admission of the state to the Union.

Atchison's law practice flourished, and his best-known client was Joseph Smith, founder of the Latter Day Saint Movement.

[10] The two became fast friends and spent many leisure time hours playing cards, going to horse races, hunting, fishing, and attending social functions and political events.

When early disputes broke out into the Mormon War of 1838, Atchison was appointed a major general in the state militia.

In October 1843,[9] Atchison was appointed to the U.S. Senate to fill the vacancy left by the death of Lewis F. Linn.

[14] King, in turn, yielded the office back to Atchison in December 1852, after being elected Vice President of the United States.

Atchison and Thomas Hart Benton, Missouri's other senator, became rivals and finally enemies, although both were Democrats.

Benton, intending to challenge Atchison in 1854, began to agitate for territorial organization of the area west of Missouri (now the states of Kansas and Nebraska) so that it could be opened to settlement.

To counter this, Atchison proposed that the area be organized and that the section of the Missouri Compromise banning slavery there be repealed in favor of popular sovereignty.

At Atchison's request, Senator Stephen Douglas of Illinois introduced the Kansas–Nebraska Act, which embodied this idea, in November 1853.

An angry Atchison called on pro-slavery Missourians to uphold slavery by force and "to kill every God-damned abolitionist in the district" if necessary.

In spite of the best efforts of Atchison and the Ruffians, Kansas rejected slavery and finally became a free state in 1861.

[19] Two days later, Atchison gave his own speech, totally unaware that he had been exposed on the Senate floor in such a fashion.

He revealed in this speech that the immediate goal of the invasion was to stop the newspaper in Lawrence from publishing anti-slavery material.

He sought election to another term, but the Democrats in the Missouri legislature were split between him and Benton, while the Whig minority put forward their own man.

Atchison actively recruited State Guardsmen in northern Missouri and served with Guard commander General Sterling Price in the summer campaign of 1861.

In September 1861, Atchison led 3,500 State Guard recruits across the Missouri River to reinforce Price and defeated Union troops that tried to block his force in the Battle of Liberty.

Atchison then resigned from the army over reported strategy arguments with Price and moved to Texas for the duration of the war.

This entailed the complete loss of his library containing books, documents, and letters documenting his role in the Mormon War, Indian affairs, pro-slavery activities, Civil War activities, and other legislation covering his career as a lawyer, senator, and soldier.

Inauguration Day—March 4—fell on a Sunday in 1849, and so president-elect Zachary Taylor did not take the presidential oath of office until the next day out of religious concerns.

[3] In September 1872, Atchison, who never himself claimed that he was technically president,[3] told a reporter for the Plattsburg Lever: It was in this way: Polk went out of office on March 3, 1849, on Saturday at 12 noon.

It was plain that there was either an interregnum or I was the President of the United States being chairman of the Senate, having succeeded Judge Mangum of North Carolina.