Atchison may have been President by fiat, but his politics after leaving office affected the larger issues of the day.

Harry S. Truman was the only U.S. president from Missouri. True or False?

True, officially. But 100 years before Truman, another Missourian technically became president—for a day. Actually, Senator David Rice Atchison, who lent his name to counties in both Missouri and Kansas, was made president sort of by default. Here's how it happened:

The term of the 11th U.S. president, James K. Polk, expired at noon on March 4, 1849. So did that of his vice president, George M. Dallas. Ordinarily, the new president, Zachary Taylor, would have been sworn in at that time. However, March 4 fell on a Sunday that year, and Taylor, a devout Episcopalian, refused to take the oath of office on the Sabbath. He put off his inauguration until the next day, Monday, March 5. The newly elected vice president, Millard Fillmore, also would not be sworn in until Monday.

That left a 24-hour gap. Under the rules of succession at that time, next in line for the presidency was the president pro tempore of the Senate, David Rice Atchison. Whether Atchison was actually president has for years been a matter of much argument. Some claim that because there was no sitting president or vice president, Atchison automatically assumed the office. Others argue that because Atchison's term as president pro tempore expired at midnight March 4, he could not have been president for more than 12 of the 24 hours. Still others say that because Atchison never took the oath of office as required by the U.S. Constitution, he was never president at all. Still, a monument at Plattsburg, Mo., proclaims David Rice Atchison was "president for a day." Take your choice.

David Rice Atchison was born on Aug. 11, 1807, at Frog Town (today called Kirklevington), Ky. He attended Transylvania University at Lexington, Ky., and studied law. When he was 23, Atchison moved to Missouri, was admitted to the Missouri bar, farmed and practiced law at Liberty, Mo. He was elected to the Missouri House of Representatives in 1834 and again in 1838. In 1841, he was appointed circuit judge in Platte County, and 2 years later—at age 36—was appointed to the U.S. Senate to fill the vacancy caused by the death of Sen. Lewis Linn. He subsequently was elected and re-elected to serve as a Democrat member of the Senate from Oct. 14, 1843 to March 3, 1855. His fellow senators elected Atchison president pro tempore for each of the 12 years he spent in the U.S. Senate.

While he was in the Senate, Atchison, a fierce pro-slavery advocate, played a major role in the passage of the Kansas-Nebraska Act in 1854—a law that helped rip the country in two. Leaving the Senate, he returned to Missouri and resumed practicing law at Plattsburg. But the former Senator had a strong passion to see slavery extended into Kansas and Nebraska, and efforts to bring that about occupied much of his time.

To understand the significance of the Kansas-Nebraska Act, it's necessary to go back a little in history. In 1820, both Maine and Missouri were petitioning for statehood. Maine was admitted as a free or non-slave state, but legislators with abolitionist sentiments blocked Missouri's admission as a slave state.

The people of Missouri threatened to split from the Union unless they were granted statehood on their own terms. But the slavery question was not just a problem of one individual state. Congressmen from the North and South looked for a way to settle the slavery question—for Missouri and territories that would apply for statehood in the future. They came up with the "Missouri Compromise," which would allow Missouri to be accepted as a slave state, but prohibited slavery in the remaining part of the Louisiana Purchase north of 36 degrees, 30 minutes latitude.

For nearly 30 years, the compromise worked, and the balance of slave and free states admitted stayed fairly even. Arkansas (slave) was admitted in 1836; Michigan (free), in 1837. In 1845, Texas entered the Union; in 1846, Iowa was granted statehood. But the balance began to get out of kilter when Wisconsin and California became free states (in 1848 and 1850, respectively) with no off-setting slave states admitted.

Then came the Kansas-Nebraska Act, which opened these mostly Indian lands to settlement and established the principle of "squatter sovereignty"—letting the residents of each territory decide whether the area would be slave or free. Most Missourians, including David Rice Atchison, assumed that Kansas would be occupied mostly by slave-holding settlers from Missouri, who would ensure the slavery status of the territory, and later the state. And, during 1854, many Missourians, whether they owned slaves or not, rushed into Kansas to claim the best settlement sites. Atchison urged these settlements by Missourians.

Abolitionists, mostly from New England, started a Kansas land rush of their own, and it soon became obvious that anti-slavery settlers intended to see Kansas enter the Union as a free state. Atchison and other pro-slavery proponents began organizing groups of men to vote in Kansas elections to prevent abolitionists from seizing the new state. At an election on March 30, 1855, to name delegates to the Kansas territorial legislature, a total of 6,307 people voted (the majority of them pro-slavery) when there were only 2,095 eligible voters in Kansas at the time. Atchison, who had led a large group across the border, said later: "We had . . . seven thousand men in the Territory on the day of the election . . . The pro-slavery ticket prevailed everywhere . . . Now let the Southern men come on with their slaves . . . We are playing for a mighty stake; if we win, we carry slavery to the Pacific Ocean."

But through 1855, the anti-slavery faction in Kansas grew rapidly. David Rice Atchison, a physically imposing man who stood six-feet-three and weighed over 200 pounds, was not afraid of violence. He began arming pro-slavery Missourians who crossed the border to vote in Kansas elections. He wrote to his friend, Jefferson Davis (who would become president of the Confederacy): "We will before 6 months rolls around, have the Devil to pay in Kansas and in [Missouri]. We are organizing to meet their organization. We will be compelled to shoot, burn and hang, but the thing will soon be over."

Before the "thing" was over, the Kansas-Missouri border would run red with blood from both factions. The violence continued, even after Kansas was admitted to the Union as a free state on Jan. 29, 1861—just weeks before the Civil War would begin in earnest.

As to David Rice Atchison's 24-hour presidency, the Missouri Senator took it lightly. By his own admission, Atchison slept through most of his term in office.

"There had been two or three busy nights finishing up the work of the Senate," he told a St. Louis Globe-Democrat reporter. "I slept most of that Sunday. Mine was probably the honestest administration this country ever had."